(Zeitschr. f. wissens. Zool., 1877, xxx, pp. 167–170, Taf. 9.)
=Plateau, Félix.= Note sur une sécrétion propre aux coléoptères
dytiscides. (Ann. Soc. Ent. Belg., 1876, v, xix, pp. 1–10.)
=Edwards, William H.= Notes on _Lycæna pseudargiolus_ and its larval
history. (Can. Ent., x, Jan., 1878, pp. 1–14. Fig.)
—— On the larvæ of _Lycæna pseudargiolus_ and attendant ants. (Can.
Ent., x, July, 1878, pp. 131–136.)
—— Butterflies of North America, i-iv. Many Pls. Phil., 1868—.
=Voges, Ernst.= Beiträge zur Kenntniss der Juliden. (Zeitsch. f.
wissens. Zoologie, xxxi, p. 127, 1878. The scent-glands are
retort-shaped bodies, the necks of which open into _foramina
repugnatoria_.)
=Rye, E. C.= Secretion of water-beetles. (Ent. Month. Mag., xiv,
1877–1878, pp. 232, 233.)
=Forel, A.= Der Giftapparat und die anal Drüsen der Ameisen. (Zeits.
f. wissens. Zool., 1878, xxx, Suppl., pp. 28–68, Taf. 3, 4.)
=Saunders, William.= Notes on the larva of _Lycæna scudderi_. (Can.
Ent., x, Jan., 1878, p. 14.)
=Weismann, A.= Ueber Duftschuppen. (Zool. Anzeiger, 26th Aug., 1878,
Jahrg., i, pp. 98, 99.)
=Gissler, Carl Friedrich.= On the repugnatorial glands in Eleodes.
(Psyche, ii, Feb., 1879, pp. 209, 210.)
—— Odoriferous glands on the 5th abdominal segment in nymph of
_Lachnus strobi_. (Fig. 273, p. 804, of Packard’s Report on Forest
and Shade Tree Insects, 1890.)
=Brunner von Wattenwyl, K.= Ueber ein neues Organ bei den Acridiodeen.
(Verhandl. k. k. Zool. Bot. Gesells. Wien., 1879, xxix;
Sitzungsber., pp. 26, 27.)
—— Verhandl. k. k. Zool. Bot. Gesells. Wien. (A peculiar organ on hind
femora of Acridiidæ.)
=Rougement, P.= Observations sur l’organe détonnant du _Brachinus
crepitans_ Oliv. (Bull. Soc. Sci. Nat. Neuchâtel, 1879, xi, pp.
471–478, Pl.)
=Goossens, Th.= Sur une organe entre la tête et la première paire de
pattes de quelques chenilles. (Ann. Soc. Ent. France, ix, p. 4,
1809; Bull., pp. 60, 61.)
—— Des chenilles vésicantes. (Ann. Ent. Soc. France, vi, pp. 461–464,
1887.)
=Coquillett, D. W.= On the early stages of some moths. (Can. Ent.,
March, 1880, xii, pp. 43–46.)
=Chambers, Victor Tousey.= Notes upon some Tineid larvæ. (Psyche, iii,
July, 1880, p. 67. Certain retractile processes “from the sides of
certain segments of the larva.”)
—— Further notes on some Tineid larvæ. (Psyche, iii, p. 135, Feb. 12,
1881. Larva of Phyllocnistis has eight pairs of lateral pseudopodia
on first eight abdominal segments.)
=French, G. H.= Larvæ of _Cerura occidentalis_ Lint, and _C. borealis_
Bd. (Can. Ent., July, 1881, xiii, pp. 144, 145.)
=Passerini, N.= Sopra i due tubercoli abdominali della larva della
_Porthesia chrysorrhœa_. (Bull. Soc. Ent. Ital., 1881, xiii, pp.
293–296.)
=Klemensiewicz, Stanislaus.= Zur näheren Kenntniss der Hautdrüsen bei
den Raupen und bei _Malachius_. (Verhandlungen d. Zool. Bot.
Gesellsch. Wien., xxxii, pp. 459–474, 1882, 2 Taf.)
=Weber, Max.= Ueber eine Cyanwasserstoffsäure bereitende Drüse.
(Archiv für Mikr. Anat., xxi, pp. 468–475, xxiv, 1882.)
=Bertkau, Philip.= Ueber den Stinkapparat von _Lacon murinus_ L.
(Archiv f. Naturg., 1882, Jahrg., xlviii, pp. 371–373.)
=Dimmock, George.= Organs, probably defensive in function, in the
larva of _Hyperchiria varia_ Walk. (_Saturnia io_ Harris). (Psyche,
iii, pp. 352, 353, Aug. 19, 1882. Account of lateral eversible
glands on 1st and 7th abdominal segments; they emit neither moisture
nor odor.)
—— On some glands which open externally on insects. (Psyche, iii, pp.
387–399, Jan. 15, 1883. Treats of poison-glands, glandular hairs,
eversible glands of Cerura, etc.)
=Coleman, N.= Notes on _Orgyia leucostigma_. (Papilio,
November-December, 1882, Jan., 1883, ii, pp. 164–166.)
=Müller, F.= Der Anhang am Hinterleibe der _Acræa_-weibchen. (Zool.
Anzeiger, 6th Aug., 1883, Jahrg., vi, pp. 415, 416.)
=Dewitz, H.= Ueber das durch die Foramina repugnatoria entleerte
Secret bei Glomeris. (Biol. Centralblatt, iv, pp. 202, 203, 1884.)
=Williston, S. A.= Protective secretion of Eleodes ejected from anal
gland. (Psyche, iv, p. 168, May, 1884.)
=Poulton, Edward Bagnall.= Notes in 1885 upon lepidopterous larvæ and
pupæ, including an account of the loss of weight in the
freshly-formed lepidopterous pupæ. (Trans. Ent. Soc., London, June,
1886, pp. 156, 157, 159.)
—— Notes in 1886 upon lepidopterous larvæ, etc. (Trans. Ent. Soc.,
London, Sept., 1887, pp. 295–301.)
—— Notes in 1887 upon lepidopterous larvæ, etc. (Trans. Ent. Soc.,
London, 1888, p. 597.)
=Künckel-d’Herculais, J.= La punaise de lit et ses appareils
odoriférants. (Comptes rendus, ciii, 1886, pp. 81–83; Annals & Mag.
Nat. Hist., 5th Ser., xviii, 1886, pp. 167, 168.)
—— Étude comparée des appareils odorifiques dans les differents
groupes d’Hemiptères hétéroptères. (Compt. rend. Acad. Sc., Paris,
cxx, pp. 1002–1004.)
=Packard, A. S.= The fluid ejected by notodontian caterpillars. (Amer.
Nat., 1886, xx, pp. 811, 812.)
—— An eversible “gland” in the larva of Orgyia. (Amer. Nat., 1886, xx,
p. 814.)
—— Fifth Rep. U. S. Ent. Comm. Insects injurious to forest and shade
trees, p. 136, 1890.
—— Hints on the evolution of the bristles, spines, and tubercles of
certain caterpillars. (Proc. Boston Soc. Nat. Hist., xxiv, 1890, p.
551.)
—— Notes on some points in the external structure and phylogeny of
lepidopterous larvæ. (Proc. Bost. Soc. Nat. Hist., xxv, 1890, pp.
83–114.)
—— A study of the transformations and anatomy of _Lagoa crispata_, a
bombycine moth. (Proc. Amer. Phil. Soc., Philadelphia, xxxii, 1893,
pp. 275–292, 7 Pls.)
—— The eversible repugnatorial scent glands of insects. (Journ., N. Y.
Ent. Soc. iii, 1895, pp. 110–127; iv, p. 896; pp. 26–32, 1 Pl.)
=Loman, J. C. C.= Freies Jod als Drüsensecret. (Tijdschr. Neder.
Dierk. Ver. Deel 1, 1887, pp. 106–108.)
=Riley, Charles Valentine.= Proc. Ent. Soc., Washington, March 13,
1888, i, pp. 87–89.
—— Notes on the eversible glands of larvæ of _Orgyia_ and _Parorgyia
leucopæa_ and _P. clintonii (achatina)_. (See 5th Rep. U. S. Ent.
Comm., p. 137.)
=Denham, Ch. S.= The acid secretion of _Notodonta concinna_. (Insect
Life, i, p. 147, 1888; hydrochloric acid.)
=Michin, Edward A.= Note on a new organ, and on the structure of the
hypodermis, in _Periplaneta orientalis_. (Quart. Journ. Micros. Sc.,
Dec., 1888, xxiv, 1 Pl.)
—— Further observations on the dorsal gland in the abdomen of
Periplaneta and its allies. (Zool. Anz., 27 Jan., 1890, pp. 41–44.)
=Maynard, C. L.= The defensive glands of a species of Phasma,
_Anisomorpha buprestoides_. (Contributions to Science, i, April,
1889.)
=Schaeffer, Cæsar.= Beiträge zur Histologie der Insekten. (Zool.
Jahrb. Morph. Abth. iii, pp. 611–652, Taf. xxix, xxx, 1889; treats
of the ventral glands in prothorax of caterpillars; scales and hairs
are secretions from the very greatly enlarged hypodermic cells.)
=Gilson, G.= Les glandes odorifères der _Blaps mortisaga_ et de
quelques autres espèces. (La Cellule, v. pp. 1–21, 1 Pl., 1889.)
—— The odoriferous apparatus of _Blaps mortisaga_. (Rep. 58th Meeting
Brit. Assoc. Adv. Sc., 1889, pp. 727, 728.)
=Haase, Erich.= Ueber die Stinkdrüsen der Orthoptera. (Sitzgsber. Ges.
Naturf. Freunde, Berlin, pp. 57, 58, 1889.)
—— Zur Anatomie der Blattiden. (Zool. Anz., xii Jahrg., pp. 169–172,
1889.)
=Herbst, Curt.= Anatomische Untersuchungen an _Scutigera coleoptrata_.
Ein Beitrag zur vergleichenden Anatomie der Articulaten. Dissert.,
Jena, pp. 36 (Hautdrüsen, Coxal-Organ.); p. 1, 1889.
=Wheeler, William M.= Hydrocyanic acid secreted by _Polydesmus
virginiensis_ Drury. (Psyche, v, p. 422.)
—— New glands in the hemipterous embryo. (Amer. Nat., Feb. 1890, p.
187; odorous(?) glands.)
=Jackson, W. Hatchett.= Studies in the morphology of the Lepidoptera,
Pt. i. (Trans. Linn. Soc., London, 2 Ser., Zoöl., v, May, 1890.)
=Krauss, Hermann.= Die Duftdrüse der _Aphlebia bivittata_ Brullé
(Blattidæ) von Teneriffa. (Zool. Anz., xiii Jahrg., 1890, pp.
584–587, 3 Figs.)
=Fernald, H. T.= Rectal glands in Coleoptera. (Amer. Nat., xxiv, pp.
100, 101, Pls. 4, 5, 1890.)
=Verson, E.= Hautdrüsen system bei Bombyciden (Seidenspinner). (Zool.
Anzeiger, 1890, pp. 118–120.)
=Vosseler, Julius.= Die Stinkdrüsen der Forficuliden. (Arch. Mikr.
Anat., xxxvi, 1890, pp. 565–578, Taf. 29.)
=Carrière, J.= Die Drüsen am ersten Hinterleibsringe der
Insektenembryonen. (Biol. Centralblatt, xi, pp. 110–127, 1891.)
=Borgert, Henry.= Die Hautdrüsen der Tracheaten. Inaugural Diss.,
Jena, 1891, pp. 1–80.
=Lang, Arnold.= Lehrbuch der vergleichende Anatomie, English Trans. by
Henry M. and Matilda Bernard, 1891, pp. 458, 459.
=Kennel, J. von.= Die Verwandtschaftverhältnisse der Arthropoden.
(Schriften herausgegeben von der Naturforscher Gesellschaft bei der
Universität Dorpat, vi, Dorpat, 1891.)
=Patton, W. H.= Scent-glands in the larva of Limacodes. (Can. Ent.,
xxiii, Feb. 1891, pp. 42, 43; eight pairs of glands with pores along
the edges of the back.)
=Batelli, Andrea.= Di una particolarita nell integumento dell’
_Aphrophora spumaria_. (Monitore Zoöl. Ital. Anno 2, pp. 30–32,
1891. Dermal glands in the hindermost segment.)
=Ash, C. D.= Notes on the larva of _Danima banksii_ Lewin. (Ent.
Month. Mag., Sept. 1892, p. 232, Fig.) notodontian larva protrudes
from under side of prothoracic segment a Y-shaped, red organ like
that of Papilio; no odor or fluid given out.
=Bernard, Henry M.= An endeavor to show that the tracheæ of the
Arthropoda arose from setiparous sacs. (Spengel’s Zool., Jahrbuch,
1892, pp. 511–524, 3 Figs.)
=Latter, Oswald.= The secretion of potassium hydroxide by _Dicranura
vinula_, and the emergence of the imago from the cocoon. (Trans.
Ent. Soc. London, 1892, 287, also xxxii; Prof. Meldola adds that the
larva of _D. vinula_ secretes strong, formic acid, and is the only
animal known to secrete a strong, caustic alkali.)
—— Further notes on the secretion of potassium hydroxide by _Dicranura
vinula_ (imago), and similar phenomena in other Lepidoptera. (Trans.
Ent. Soc. London; Nature, 1895, p. 551, March 20, 1895.)
=Zograff, Nicolas.= Note sur l’origine et les parentes des
Arthropodes, principalement des Arthropodes trachèates. (Congrès
Internationale de Zoologie, 2^e Session à Moscow, Aug. 1892; Part i,
Moscow, 1892, pp. 278–302, 1892; cyanogenic glands in Myriopods, p.
287.)
=Swale, H.= Odor of _Olophrum piceum_. (Ent. Month. Mag., v, Jan.
1896, pp. 1, 2.)
=Cuénot, L.= Moyens de défense dans la série animale, Paris, n. d.
(1892); the ejection of blood as a means of defence by some
Coleoptera. (Comptes rendus, Acad. Sc. France, April 16; Nature,
April 26, 1894.)
—— Sur la saignée réflexe et les moyens de défense de quelques
insectes. (Arch. Zool. expér. (3), 1897, iv, pp. 655, 679, 680.)
=Holmgren, Emil.= Studier öfverhudens och de körtelartade hudorganens
morfologi hos skandinaviska macrolepidopterlarver. (K. Svenska
Vetenskaps-Akademiens Handlingar, xxvii, No. 4, Stockholm, 4º 1895,
pp. 82, 9 Pls.)
=Lutz, K. G.= Das Blut der Coccinelliden. (Zool. Anzeiger, 1895, pp.
244–255, 1 Fig.)
=Gilson, Gustav.= Studies in insect morphology. (Proc. Linn. Soc.
London, March 5, 1896; Nature, p. 500.)
—— On segmentally disposed thoracic glands in the larvæ of the
Trichoptera. (Journ. Linn. Soc., London, xxv. 1897.)
=Cholodkowsky, N.= Entomotomische Miscellen, v, Ueber die
Spritzapparate der Cimbiciden Larven, pp. 135–143, 2 Taf. Ibid., vi.
Ueber das Bluten der Cimbiciden Larven, pp. 352–357, 1 Fig. (Horæ
Soc. Ent. Rossicæ, xxx, 1897.)
Also the writings of Darwin, Wallace, Poulton, Weir, Beddard, Butler,
Busgen, (pp. 365–367), Girard, Kolbe, Locy.
THE ALLURING OR SCENT-GLANDS
It is difficult to draw the line between repelling and alluring glands.
Attention was first definitely called to the alluring odors of
Lepidoptera by Fritz Müller, who showed that the males of certain
butterflies are rendered attractive to the other sex by secreting
odorous oils of the ether series. He pointed out that the seat of the
odor is the androconia (see p. 199), while either repellent or pleasant
odors are exhaled from abdominal glands.
Those of _Pieris napi_ yield a scent like that of citrons, _Didonis
biblis_ gives off three different odors from different parts of the
body, besides having a distinctly odorous spot on the hind wings.
Both sexes have a sac between the fourth and fifth abdominal
segments which exhales a very unpleasant (protective) odor, while
the males have on the succeeding segment a pair of glands from which
proceeds an agreeable odor like that of the heliotrope. _Callidryas
argante_ throws off a musky odor. In _Prepona laertes_ the odor is
like that of a bat, in _Dircenna xantho_ it is vanilla-like, the
androconia being situated on the front edge of the hind wings. In
_Papilio grayi_ the odor is said to be as agreeable and intense as
in flowers. Certain sphingids are known to exhale a distinct odor,
which Müller has traced to a tuft of hair-like scales at the base of
the abdomen, and which fits into a groove in the first segment, so
as to be ordinarily invisible.
[Illustration:
_Fig. 367._—Scent-tufts: 1, of _Leucarctia acræa_; 2, of _Pyrrarctia
isabella_.—After Smith.
]
In the noctuid genus, Patula, the costal half of the hind wing is
modified to form a large scent-gland, and in consequence the
venation has been modified. The still greater distortion of the
veins in the allied genus, Argida, was attributed by the author to
its once having possessed a similar scent-gland, now become
rudimentary by disuse. (Hampson.)
Peculiar white or orange-colored, hairy, thread-like processes have
been found protruding from narrow openings near the tip of the
abdomen of Arctian moths (Fig. 367), which throw off, according to
J. B. Smith, “an intense odor, somewhat like the smell of laudanum.”
We have perceived the same unpleasant odor emanating from the males
of _Spilosoma virginica_ and _Arctia virgo_, as well as _Leucarctia
acræa_.
We are informed by C. Dury that similar but longer hairy appendages
are thrust out by the male of _Haploa clymene_. Many glaucopid moths
protrude similar glandular processes. Thus Müller tells us that on
seizing a glaucopid female by the wings, nearly the whole body
became enveloped in a large cloud of snow-white wool which came out
of a sort of pouch on the ventral side of the abdomen.
The male of a glaucopid was seen to dart out a pair of long hollow
hairy retractile filaments which in some species exceed the whole
body in length. The apparatus secretes a peculiar odor, probably
serving to allure the female (Nature), and certain Zygænidæ have on
the inner side of the paranal lobes (Afterklappen) glands filled
with a sweetly scented fluid. Smith has detected a peculiar brush of
hair-like scales in a groove between the dorsal and ventral parts of
the basal two segments of the abdomen of _Schinia marginata_ (family
Noctuidæ), and when removed it exhaled a laudanum-like smell.
The pupa of _Citheronia regalis_ gives out from the end of the
abdomen a scent reminding us of laudanum.
[Illustration:
FIG. 368.—Scent-tufts on middle legs of _Catocala concumbens_.—After
Bailey.
]
Another mode of disseminating pleasant, alluring odors is that of the
males of certain moths, which bear pencils and tufts on their fore or
hind legs, and in the case of an Indian butterfly on the greatly
elongated palpi. Those on the legs are ordinarily concealed in cavities
or furrows in the leg, and may be thrust out and expanded so as to
widely diffuse their odor. Such are those of the males of Catocala (Fig.
368), which resemble an artist’s fitch brush. In _Hepialus hecta_, where
the arrangements for protecting the tufts are quite abnormal, Bertkau
has detected the cells which secrete the odorous fluid. In the male of
another Hepialus (_H. humuli_) a peculiar scent proceeds from the
curiously aborted and altered hind tibiæ. (Barrett.) In one case, that
of a geometrid moth (_Bapata dichroa_ of New Guinea), these pencils
occur on all the legs. (Haase). In many species a distinct odor is
perceptible when the leg bearing the pencil or tuft is crushed.
These eversible scent-glands have been supposed to be mostly restricted
to the Lepidoptera, and to a single known case in the Trichoptera, but
similar alluring male glands also occur in the Orthoptera (Locustidæ).
H. Garman has described and figured in the cave cricket (_Hadenœcus
subterraneus_) “a pair of white fleshy appendages protruding from slits
between the terga of the 9th and 10th abdominal somites, the nature of
which is not clear,” adding, “the slits through which the organs appear
are situated one on each side anterior to and a little within the cerci.
When fully protruded, the glands are white, cylindrical, a little
tapering, and are about one-eighth of an inch long.” He believes that
they are protruded during the period of sexual excitement, and suggests
that “the sense of smell is certainly the one best calculated to bring
the sexes together in the darkness of caves.” We had previously noticed
these organs in alcoholic specimens, but supposed that they were fungous
growths. On dissecting and making microscopic sections of them, the
gland is, when extended (Fig. 369), seen to be a long, ensiform, sharp,
band-like process, with numerous retractor muscular fibres. When at rest
each gland is folded about five times, forming a bundle lying on each
side of the end of the intestine. The walls are formed of a single layer
of epithelium, as seen in Fig. 369, _B_.
[Illustration:
FIG. 369.—Eversible scent-glands (_a_) of Hadenœcus, nat. size:
Kingsley, _del._; _A_, a gland outstretched, with the retractor
muscular fibres; _t_, part of the tergite. _B_, section of the
gland, showing the single layer of epithelial cells, and the
muscular fibres (_m_).—Author _del._
]
In the male of the common wingless cricket, _Ceuthophilus maculatus_, we
have discovered what appears to be a pair of scent-glands lying directly
over the last abdominal ganglion. They form two large white sacs
situated close together, with a short common duct which passes back and
opens externally upwards by a transverse slit on the under side of the
last segment of the body.
LITERATURE ON ALLURING GLANDS
=Watson, J.= On the microscopical examination of plumules, etc. (Ent.
Month. Mag., ii, 1865, p. 1.)
—— On certain scales of some diurnal Lepidoptera. (Mem. Lit. and Phil.
Soc. Manchester, Ser. 3, ii, 1868, p. 63.)
—— On the plumules or battledore scales of Lycænidæ. (Mem. Lit. and
Phil. Soc. Manchester, Ser. 3, iii, 1869, p. 128.) Further remarks,
etc. (Ibid., p. 259.)
=Anthony, J.= Structure of battledore scales. (Month. Microsc. Journ.,
vii, 1872, p. 250; see also p. 200.)
=Morrison, Herbert Knowles.= On an appendage of the male _Leucarctia
acræa_. (Psyche, i, pp. 21–22, October, 1874.)
=Müller, Fritz.= The habits of various insects. (Nature, June 11,
1874, pp. 102–103.)
—— Ueber Haarpinsel, Fitzflecke und ähnliche Gebilde auf den Flügeln
männlicher Schmetterlinge. (Jena. Zeitschr. f. Naturw., 1877, xi,
pp. 99–114.)
—— Beobachtungen an brasilianischen Schmetterlingen, ii. I. Die
Duftschuppen der männlichen Maracujáfalter. (Kosmos, 1877, i, pp.
391–395, Figs. 5, 6.) II. Die Duftschuppen des männchens von _Dione
vanillæ_. (Kosmos, ii, 1877, pp. 38–42, 7 Taf.)
—— As maculas sexuaes dos individuos masculinos das especies _Danais
erippus_ e _D. gilippus_. (Arch. Mus. Nac. Rio Janeiro, ii, 1877
(1878), pp. 25–29, 1 Pl.)
—— Die Duftschuppen der Schmetterlinge (nach dem “Kosmos” in Ent.
Nachr., 1878, pp. 29–32, 109).
—— Wo hat der Moschusduft der Schwärmer seinen Sitz? (Kosmos, ii
Jahrg., 1878, pp. 84, 85.)
—— Os orgaos odoriferos dos especias _Epicalia acontius_, Lin. e de
_Myscelia orsis_, Dru. (Arch. Mus. Nac. Rio Janeiro, ii, 1879, pp.
31–35.)
—— Os orgaos odoriferos nas pernas de certos Lepidopteres. (Arch. Mus.
Nac. Rio Janeiro, ii, 1879, pp. 37–46, 3 Pls.)
—— Os orgaos odoriferos da _Antirrhœa archœa_. (Arch. Mus. Nac. Rio
Janeiro, iii, 1878, pp. 1–7, 1 Pl.)
—— A prega costal das Hesperideas. (Arch. Mus. Nac. Rio Janeiro, iii,
1880, pp. 41–50, 2 Pls.)
=Weismann, August.= Ueber Duftschuppen. (Zool. Anzeiger, i, 1878, pp.
98, 99.)
=Arnhart, L.= Sexundäre Geschlechtscharaktere von _Acherontia
atropos_. (Verh. d. k. k. zool. bot. Ges. Wien, xxix, 1879, p. 54.)
=Bertkau, Philipp.= Duftapparat an Schmetterlingsbeinen. (Ent.
Nachrichten, 1879, Jahrg., pp. 223, 224.)
—— Ueber den Duftapparat von _Hepialus hecta_. (Archiv f. naturg.,
xlviii Jahrg., 1882, pp. 363–370, Figs.; also in Biol.
Centralblatt., ii Jahrg., 1882, pp. 500–502.)
—— Ergänzung (Duftvorrichtungen bei Lepidopteren). (Ent. Nachr., 1880,
p. 206.)
—— Entomologische Mizellen. 1. Ueber Duftvorrichtungen einiger
Schmetterlinge. (Verh. d. naturhist. Ver. d. preuss. Rheinlande und
Westf., 1884, pp. 343–350.)
=Reichenau, W. von.= Der Duftapparat von _Sphinx ligustri_. (Ent.
Nachr., 1880, p. 141; also Kosmos, iv Jahrg., 1880, pp. 387–390.)
=Fügner, R.= Duftapparat bei _Sphinx ligustri_. (Ent. Nachr., 1880, p.
166.)
=Lelievre, Ernest.= (Note in Le Naturaliste, June 1, 1880. Both sexes
of _Thais polyxena_ emit an odorous exhalation. Notes on exhalation
from _Spilosoma fuliginosa._)
=Hall, C. G.= Peculiar odor emitted by _Acherontia atropos_.
(Entomologist, London, xvi, p. 14.)
=Åurivillius, Christopher.= Ueber secundäre Geschlechtscharactere
nordischer Tagfalter. (Stockholm, 1880, Bihang till K. Svensk. Vet.
Akad. Handl., v, pp. 56, 3 Taf.)
—— Des caractères sexuels secundaires chez les papillons diurnes.
(Ent. Tidskrift, 1880, pp. 163–166.)
—— Anteckningar om några skandinaviska fjärilarter. (Ent. Tidskr., iv,
Årg., 1884, pp. 33–37; Résumé (French), ibid., pp. 55–57.)
=Kirby, W. F.= Fans on the fore legs of _Catocala fraxini_. (Papilio,
ii, p. 84, 1882.)
=Bailey, James S.= Femoral tufts or pencils of hair in certain
Catocalæ. (Papilio, ii, 1882, pp. 51, 52, 146; also in Stettin Ent.
Zeitung, xliii, p. 392.)
=Edwards, Henry.= Fans on the feet of Catocaline moths. (Papilio, ii,
p. 146, 1882.)
=Stretch, R. H.= Anal appendages of _Leucarctia acræa_. (Papilio, iii,
pp. 41, 42, 1883, 1 Fig.)
=Weed, Clarence M.= Appendages of Leucarctia. (Papilio, iii, 1883, p.
84.)
=Grote, Aug. R.= Appendages of _Leucarctia acræa_. (Papilio, iii,
1883, p. 84.)
=Haase, Erich.= Ueber sexuelle Charactere bei Schmetterlingen.
(Zeitschr. f. Ent., Breslau, N. F., 1885, pp. 15–19, 36–44; also
Ent. Nachr., xi Jahrg., pp. 332, 333.)
—— Duftapparate indo-australischer Schmetterlinge. (Corresp. Blatt.
Ent. Ver. Iris, Dresden, 1886, pp. 92–107, 1 Taf.; ibid., 1887, pp.
159–178; ibid., 1888, pp. 281–336.)
—— Ueber Duftapparate bei Schmetterlingen. (Sitzgsber. Nat. Ges. Iris,
Dresden, 1886, pp. 9–10; Abstr. in Journ. R. Micr. Soc., vi, pp.
969–970, 1886.)
—— Der Duftapparate von Acherontia. (Zeitschr. f. Ent., Breslau, N.
F., 1887, pp. 5–6.)
—— Dufteinrichtung indischer Schmetterlinge. (Zool. Anzeiger, 1888,
pp. 475–481.)
=Dalla Torre, K. W. von.= Die Duftapparate der Schmetterlinge.
(Kosmos, 1885, ii, pp. 354–364, 410–423; Abstr. by J. B. Smith in
Proc. Ent. Soc., Washington, i, pp. 38, 1888.)
=Smith, John B.= _Cosmosoma omphale._ (Entomologica Americana, i, pp.
181–185, 1886. Describes and figures cavities in under side of
2d–4th abdominal segments of male, filled with a silky substance.
This may be for display to attract ♀, as the whole mass must be very
conspicuous when protruded. No odor noticed.)
—— Scent organs in some Bombycid moths. (Entomologica Americana, ii,
No. 4, pp. 79–80, 1886. Describes and figures long, slender, forked
hairy, orange or white, eversible glands, everted from between 7th
and 8th segments of abdomen of ♂ of _Leucarctia acræa_, _Pyrrharctia
isabella_, _Scepsis fulvicollis_, and _Cosmosoma omphale_.)
—— [Notes on odors and odoriferous structures of various moths and a
note by L. O. Howard on odor of Dynastes.] (Proc. Ent. Soc.,
Washington, i, pp. 40, 55, 56.)
=Müller, W.= Duftorgane der Phryganiden. (Archiv f. Naturgesch., 1887,
Jahrg. liii, pp. 95–97.)
=Pollack, W.= Duftapparate der _Hadena atriplicis_ und Litargyria. (xv
Jahrb. Westphäl. Prov. Ver. Münster, 1887, p. 16.)
=Patton, W. H.= Scent-glands in the larva of Limacodes. (Can. Ent.,
1891, xxiii, pp. 42, 43.)
=Garman, H.= On a singular gland possessed by the male _Hadenœcus
subterraneus_. (Psyche, 1891, p. 105, 1 Fig.)
=Barrett, C. G.= Scent of the male _Hepialus humuli_. (Ent. Month.
Mag., Ser. 2, iii, 1892, p. 217. Arises from the curiously aborted
and altered hind tibiæ.)
Also the writings of Baillif, Duponchel, F. Müller, Scudder (Psyche,
iii, p. 278, 1881), Burgess, Keferstein, Alpheraky, Plateau,
Marshall and Nicéville, Wood-Mason, White, Hampson.
THE ORGANS OF CIRCULATION
Although Malpighi was the first to discover the heart in the young
silkworm, it was not until 1826 that Carus proved that there was a
circulation of blood in insects, which he saw flowing along each side of
the body, and coursing through the wings, antennæ, and legs of the
transparent larva of Ephemera, though three years earlier Herold
demonstrated that the dorsal vessel of an insect is a true heart,
pulsating and impelling a current of blood towards the head. This
discovery was extended by Straus-Dürckheim, who discovered the
contractile and valvular structures of the heart. It is noteworthy that
both Cuvier and Dufour denied that any circulation, except of air,
existed in insects; and so great an anatomist as Lyonet doubted whether
the dorsal vessel was a genuine heart, though he pointed out the fact
that there are no arteries and veins connected with this vessel. Another
French anatomist, Marcel de Serres, thought that the dorsal vessel was
merely the secreting organ of the fat-body.
The so-called peritracheal circulation claimed by Blanchard and by
Agassiz has been shown by McLeod to be an anatomical impossibility,
the view having first been refuted by Joly in 1849.
Except the aorta-like continuation in the thorax and head which
divides into two short branches, there are, with slight exceptions
(p. 405), no distinct arteries, such as are to be found in the
lobster and other Crustacea, and no great collective veins, such as
exist in Crustacea and in Limulus. This is probably the result of a
reduction by disuse in the circulatory system, since in myriopods
(Julidæ and Scolopendridæ) lateral arteries are said to diverge near
the ostia.
_a._ The heart
The heart or “dorsal vessel” is a delicate, pulsating tube, situated
just under the integument of the back, in the median line of the body,
and above the digestive canal. It can be partially seen without
dissection in caterpillars. It is covered externally and lined within by
membranes which are probably elastic; and between these two membranes
extends a system of delicate muscular fibres, which generally have a
circular course, but sometimes cross each other. The heart is divided by
constrictions into chambers, separated by valvular folds. The internal
lining membrane referred to forms the valvular folds separating the
chambers. Each of these chambers has, at the anterior end, on each side,
a valvular orifice (Fig. 370, ostium, _i_) which can be inwardly closed.
Miall and Denny thus describe the different layers of the wall of
the heart of the cockroach:
“There are: (1) a transparent, structureless intima, only visible
when thrown into folds; (2) a partial endocardium, of scattered,
nucleated cells, which passes into the interventricular valves; (3)
a muscular layer, consisting of close-set, annular, and distant,
longitudinal fibres. The annular muscles are slightly interrupted at
regular and frequent intervals, and are imperfectly joined along the
middle line above and below, so as to indicate (what has been
independently proved) that the heart arises as two half-tubes, which
afterwards join along the middle. Elongate nuclei are to be seen
here and there among the muscles. The adventitia (4), or connective
tissue layer, is but slightly developed in the adult cockroach.”
[Illustration:
FIG. 370.—Part of the heart of _Lucanus cervus_: _a_, the posterior
chambers (the anterior ones are covered by a part of the ligaments
which hold the heart in place); _i_, auriculo-ventricular openings;
_g_, _g_, the lateral muscles fixed by the prolongations _h_, _h_,
to the upper side of the abdomen.—After Straus-Dürckheim.
]
Graber says that the heart of insects may be regarded not as an organ
_de novo_, but only as the somewhat modified contractile dorsal vessel
of the annelids, in which, however, the transverse arteries arising on
each side became, with the gradual development of the tracheæ,
superfluous and finally abortive. He describes it as a muscular tube
composed of very delicate annular fibres, which within and without is
covered by a relatively homogeneous, strong, elastic membrane.
The division into separate chambers is effected by means of a
folding inwards and forwards of the entire muscular wall. “A portion
of each side of the heart is first extended inwards so as very
nearly to meet a corresponding portion from the opposite side, and
then, being reflected backwards, forms, according to Straus
(Consid., etc., p. 356), the interventricular valve which separates
each chamber from that which follows it. Posteriorly to this valve,
at the anterior part of each chamber, is a transverse opening or
slit (Fig. 371, _b_), the _auriculo-ventricular orifice_, through
which the blood passes into each chamber, and immediately behind it
is a second, but much smaller, _semilunar valve_ (_c_), which, like
the first, is directed forwards into the chamber. It is between
these two valves on each side that the blood passes into the heart,
and is prevented from returning by the closing of the semilunar
valve. When the blood is passing into the chamber, the
interventricular valve is thrown back against the side of the
cavity, but is closed when, by the contraction of the transverse
fibres, the diameter of each chamber is narrowed, and the blood is
forced along into the next chamber.” (Newport.)
[Illustration:
FIG. 371.—A, heart of _Lucanus cervus_: _a_, valves or chambers;
_bb_, alary muscles; _c_, supposed auricular space around the
heart. _B_, division into arteries of the end of the aorta in
larva of _Vanessa urticæ_. _C_, interior of the chamber, showing
the transverse fibres; _b_, auriculo-ventricular opening and valve
into the chambers; _c_, semilunar valve; _d_, interventricular
valve.—After Straus-Dürckheim, from Newport.
]
[Illustration:
FIG. 372.—Heart of Belostoma.—After Locy.
]
According to Müller, there is but a single pair of ostia in Phasma,
and, in the larva of Corethra, the heart is a simple, unjointed
tube, not divided into chambers, and Viallanes states that, in the
very young larva of Musca, there are no ostia (Kolbe). In the larva
of Ptychoptera, Grobben found a short oval heart, with one pair of
ostia situated in the 6th abdominal segment; a long aorta proceeds
from it, the thoracic portion of which pulsates; from behind the
heart arises a pulsating pouch, which connects with the hinder
aorta, which does not pulsate, and ends at the base of two tracheal
gills. Burmeister was able to find only four pairs of openings in
the larva of Calosoma. Newport states that, while Straus figures
nine chambers in Melolontha, and, consequently, eight pairs of
openings, he has not been able to observe more than seven pairs of
openings in _Lucanus cervus_. He has invariably found eight pairs of
openings both in the larva and imago of _Sphinx ligustri_, as well
as in other Lepidoptera. According to Béla-Dezso, the number of
pairs of ostia corresponds to that of the pairs of stigmata.
There also occur, on each side of each chamber, two so-called
pear-shaped bodies which are separated from the tubular portion of
the heart itself, but, by means of muscular fibres, are united with
the chamber and with their valves. These pyriform bodies appear as
vesicles or cells with granular contents, besides some nuclei with
nucleoli. They are of very small size. According to the measurements
of Dogiel, in the larva of _Corethra plumicornis_, they are 0.02 to
0.1 mm. long, and 0.06 to 0.08 mm. broad. He regards these peculiar
bodies as apolar nerve-cells of the heart. (Kolbe.)
[Illustration:
FIG. 373.—A, part of the heart of _Dyticus marginalis_, showing the
spiral arrangement of the muscular fibres; _c_, closed, _e_, open,
valve; _a_, dorsal diaphragm with interwoven muscular fibres; _b_,
arrangement of fibres, recalling the screw-like features of the
fibres of the human heart; _d_, narrow end. _B_, diagrammatic
figure of the valvular openings, with the terminal flap (_e_), and
the cellular valve, of a May beetle; _a_, valvular opening of a
dipterous larva, with the interventricular valve (_b_). _C_,
abdomen of a mole-cricket, ventral view; _c_, the segmented heart;
_a_, aorta; _b_, segmented diaphragm under it.—After Graber.
]
Besides the venous openings of the heart which open into the
pericardial region, Kowalevsky has discovered, in the heart of some
Orthoptera (Caloptenus, Locusta, etc.), five pairs of openings by
which the cardiac chambers receive the blood of the peri-intestinal
region. Graber had divided the cœlom of insects into three regions
(pericardial, peri-intestinal, and perineural regions), and hitherto
only a union of the heart with the pericardial region by slit-like
openings was known. These openings are symmetrically distributed on
five abdominal segments; each section of the heart in this region
has, therefore, four openings, which are all of a truly venous
nature. These openings, called cardio-cœlomic apertures, are visible
to the naked eye, being situated on conical papillæ of the walls of
the heart. These papillæ pass through the outer diaphragm, and open
into the peri-intestinal part of the cœlom, in the Acrydiidæ
directly, in the Locustidæ through special canals. The cells of the
papillæ are spongy, possessing large nuclei, and similar, as a
whole, to glandular cells. (Comptes rendus, cxix, 1894.)
The mechanism by which the ostia are closed consists, according to
Graber, of an ∞-shaped muscle passing around the two openings, and
which, being interlaced, is sufficient to close the openings. But
this is not all. The fore and hinder edge of the ostia project,
leaf-like, into the cavity of the heart, and thus form, with the
outer walls, two valves which, during the systole, filled with the
blood rushing in, not only hermetically close the lateral openings,
but also, by the simultaneous closure of the entire chamber by the
circular muscles in the middle of the same, the two valves,
simultaneously approaching each other, so nearly touch that they
form a transverse partition wall in the chamber. But, for the last
purpose, _i.e._ for the separation of the chambers from one another,
there is a very special contrivance. In the May beetle, we find,
besides a valve (Fig. 373, _B_, _e_), opening into the middle of the
chambers, a large, stalked cell (_d_), which, in the diastole,
_i.e._ in the expansion of the heart, hangs down free on the walls
of the heart; but, in the systole or contraction, like a cork,
closes the middle of the valve, but does not wholly close the
cavity. He has observed, in the larva of Corethra, formal,
interventricular valves, which also are not in the middle, but are
separated from one another in the interlaced ends. They consist of
two longitudinally membranous flaps which move against each other
like two valves (Fig. 373, _B_, _b_).
“But what is the necessity for such a complicated mechanism? All the
blood from behind passes into the heart, and, for its propulsion a
simple muscular tube, whose circular fibres would draw together and
contract it, would be thought to be sufficient. But the heart,
except in some larvæ, ends posteriorly in a blind sac, and the blood
can only pass into it by a series of pairs of lateral openings. Now,
as regards the reception and the propulsion of the blood forwards,
two modes are conceivable. The simplest way would be that the
tubular heart should, along its whole length, contract or expand;
that, moreover, the blood should be simultaneously sucked in through
all the openings, and that then, also, the contraction, or systole,
should take place in every part of the heart at the same moment. But
this would, plainly, in so long and thin-walled a vessel, be highly
impracticable, since, through such a manipulation, the mass of blood
enclosed in the heart would be crowded together rather than really
impelled forwards. Only the second case could be admissible, and
that is this, that each chamber pulsates, one after another, from
behind forwards. But, then, each segmental heart must be separated
from the others by a valve. To make the matter wholly clear, we may
observe an insect heart pulsating, and this is best seen in one of
its middle chambers. This chamber expands (simply by the relaxation
of its circular muscles), the ostia, also, consequently open, and a
given quantity of blood is drawn in from the pericardial cavity.
What now would happen after the succeeding contraction if there were
no valves between? The blood would not flow forwards, but seek a way
out backwards.
“But, in fact, the valve of the hinder chamber, at this time, closes
itself, while, by the simultaneous expansion of the anterior ones,
their door opens, and this section of the heart, at the same time,
causes a sucking in of the contents of the posterior chamber. This
phenomenon is repeated, in the same way, from chamber to chamber,
which also acts alternately as ventricle and auricle, or by a
sucking and pumping action. One is involuntarily reminded of the
ingenious manipulation by which, by the alternate opening and
shutting of the flood-gates, a vessel is carried along a canal.
“This wave-like motion of an insect’s heart also has the advantage
that, just before a pulse-wave has reached the chambers farthest in
front, the hinder ones are already prepared for the production of a
second, for, as a matter of fact, often 60, and even 100, and, in
very agile insects, 150, waves pass, in a single minute, through the
series of chambers, which make it very difficult to follow the
flowing of their waves.” (Graber.)
=The propulsatory apparatus.=—But the heart itself is only a part of
the entire propulsatorial apparatus to which belongs the following
contrivance, the nature of which has been worked out by Graber.
Under the dorsal vessel is stretched a sort of roof-like diaphragm,
_i.e._ a membrane, arched like the dorsal wall of the hind-body
which is attached, in a peculiar way, to the sides of the body. The
best idea can be gained by a cross-section through the entire body
(Fig. 374): _H_ is the true dorsal vessel; _S_, the diaphragm. A
surface view is seen at 373, _C_, _b_, where it appears as a plate
with the edge regularly curved outwards on each side. Its precise
mode of working is thus: from each dorsal band of the sides of the
abdomen arises a pair of muscles spreading out fan-like, and
extending to the heart, so that the fibres of one side pass directly
over to those of the other, often splitting apart, or, between the
two, extends outwards a perforated, thin web, like an elastic,
fibrous sheet (Fig. 373, _A_, _a_), with numerous perforations,
forming a diaphragm.
[Illustration:
FIG. 374.—Diagram of transverse section of pericardial sinus of
_Ædipoda cœrulescens_: _H_, heart; _s_, septum; _m_, muscles,—the
upper suspensory, the lower alary.—After Graber, from Sharp. (See
also Fig. 377.)
]
Graber has thus explained the action of the pericardial diaphragm
and chamber, as freely translated by Miall and Denny: “When the
alary muscles contract, they depress the diaphragm, which is arched
upwards when at rest. A rush of blood towards the heart is thereby
set up, and the blood streams through the perforated diaphragm into
the pericardial chamber. Here it bathes a spongy or cavernous tissue
(the fat-cells), which is largely supplied with air-tubes, and
having been thus aerated, passes immediately forwards to the heart,
entering it at the moment of diastole, which is simultaneous with
the sinking of the diaphragm.”
In the cockroach, however, Miall and Denny think that the facts of
structure do not altogether justify this explanation: “The fenestræ
of the diaphragm are mere openings without valves. The descent of a
perforated non-valvular plate can bring no pressure to bear upon the
blood, for it is not contended that the alary muscles are powerful
enough to change the figure of the abdominal rings.... The diaphragm
appears to give mechanical support to the heart, resisting pressure
from a distended alimentary canal, while the sheets of fat-cells, in
addition to their proper physiological office, may equalize small
local pressures, and prevent displacement. The movement of the blood
towards the heart must (we think) depend, not upon the alary
muscles, but upon the far more powerful muscles of the abdominal
wall, and upon the pumping action of the heart itself.”
“The peculiar office,” says Graber, “performed by the heart has
already been stated. It is nothing more than a regulator; than an
organ for directing the blood in a determinate course in order that
this may not wholly stagnate, or only be the plaything of a force
acting in another way, as, for example, through that afforded by the
body-cavity and the inner digestive canal. At regular intervals a
portion of the blood is sucked through the same, and then by means
of the anterior supply tube it is pushed onward into the head,
whence it passes into the cavities of the tissues. The different
conditions of tension under which the mass of blood stands in the
different regions of the body then causes a farther circulation.
Besides this, the blood passes through separate smaller pumping
apparatuses, and through vessel-like modifications of cavities, also
through hollow spaces between the muscles, as, for example, in the
appendages where a regular backward and forward flow of the blood,
especially in the limbs, wings, antennæ, and certain abdominal
appendages takes place. Here and there may occasionally occur a
narrow place where the flow of blood is obstructed by the
accumulation of the blood corpuscles, causing a considerable
stagnation.” (Graber.)
[Illustration:
FIG. 375.—_Libellula depressa_, opened from the back, showing the
nervous cord (_b_{1}_-_b_{3}_, thoracic, _h_{1}_-_h_{7}_, abdominal,
ganglia), also the furrow-like ventral sinus closed by a muscular
diaphragm.
]
[Illustration:
FIG. 376.—_A_, part of the ventral furrow of _Libellula depressa_ more
highly magnified: _a_, a sternal plate (urite); _c_, the septum
stretched over it, at _s_ in a relaxed or collapsed state; _b_ and
_d_, the wing-like, sternal processes from which the muscular
bundles of the diaphragm arise. _B_, same in Acridium.
]
[Illustration:
FIG. 377.—Diagrammatic section of the abdomen of _Acridium
tartaricum_, showing the ventral septum (_i_, _p_, _l_) contracted,
and (_i_, _k_, _l_) stretched out; _oh_, rib-like lateral processes
of the urite; _f_, ganglia; _b_, heart, with its suspensorium (_a_);
_c_, fat tissue in the pericardial tissue sinus; _d_, dorsal septum
or diaphragm contracted. _q_, extended; _g_, fat-body; _e_, muscular
part of diaphragm; _no_, expiration, _hm_, inspiration, muscle.—This
and Figs. 375, 376, after Graber.
]
=The supraspinal vessel.=—In many insects there is a ventral heart
acting on the heart’s blood as an aspirator, or more correctly a ventral
sinus lying on the nervous cord, and closed by a pulsating diaphragm.
This was discovered by Réaumur in the larva of a fly, and by Graber in
the dragon-fly and locusts (Acrydiidæ). A glance at Figs. 375 and 376
will save a long description. The ventral wall forms a furrow, and
between its borders (Fig. 377, _e_) extends the diaphragm. During the
contraction of the muscles—and this, here, acts from before
backwards—the membrane rises up and makes a cavity for the blood, which
passes backwards over the nervous cord. The dorsal and ventral sinuses
together thus bring about a closed circulation.
It thus appears that the insects are well provided with the means of
distribution of their nutritive fluid, and that the blood is kept
continually fresh and rich in oxygen. (Graber.)
=The aorta.=—While the heart is mostly situated within the abdomen, it
is continued into the thorax and the head as a simple, non-pulsating
tube, called the aorta. In Sphinx the aorta, as described by Newport,
begins at the anterior part of the 1st abdominal segment, where it bends
downwards to pass under the metaphragma and enter the thorax; it then
ascends again between the great longitudinal dorsal muscles of the
wings, and passes onwards until it arrives at the posterior margin of
the pronotum; it then again descends and continues its course along the
upper surface of the œsophagus, with which it passes beneath the brain,
in front of which and immediately above the pharynx, it divides into two
branches, each of which subdivides. Newport, however, overlooked a
thoracic enlargement of the aorta called by Burgess the “aortal chamber”
(Fig. 310, _a_, _c_).
[Illustration:
FIG. 378.—_A_, last three abdominal segments and bases of the three
caudal processes of _Cloëon dipterum_: _r_, dorsal vessel; _kl_,
ostia; _k_, special terminal chamber of the dorsal vessel with its
entrance _a_; _b_, blood-vessel of the left caudal process. _B_,
26th joint of the left caudal appendage from below: _b_, a portion
of the blood-vessel; _o_, orifice in the latter.—After Zimmermann,
from Sharp.
]
“In Sphinx and _Vanessa urticæ_, immediately after the aorta has
passed beneath the cerebrum, it gives off laterally two large
trunks, which are each equal in capacity to about one-third of the
main vessel. These pass one on each side of the head, and are
divided into three branches which are directed backwards, but have
not been traced farther in consequence of their extreme delicacy.
Anterior to these trunks are two smaller ones which appear to be
given to the parts of the mouth and antennæ, and nearer the median
line are two others which are the continuations of the aorta. These
pass upwards, and are lost in the integument. The whole of these
parts are so exceedingly delicate that we have not, as yet, been
able to follow them beyond their origin at the termination of the
aorta, but believe them to be continuous, with very delicate,
circulatory passages along the course of the tracheal vessels. It is
in the head alone that the aorta is divided into branches, since,
throughout its whole course from the abdomen, it is one continuous
vessel, neither giving off branches, nor possessing lateral muscles,
auricular orifices, or separate chambers.” (Newport, art. Insecta,
p. 978.)
Dogiel observed in the transparent larva of _Corethra plumicornis_ that
the aorta extends only to the hinder border of the brain. Here it
divides into two lamellæ, each of which independently extends farther
on. One lamella is seen under the brain and under the eye, the other
reaches near the eye. The lamellæ are tied to the integument by threads.
At the point of division of the aorta is an opening. (Kolbe.)
True blood-vessels appear to exist in the caudal appendages of the
May-flies, as the heart appears to divide and pass directly into
them (Fig. 378). The last chamber of the heart diminishes in size at
the end of the body, and then divides into three delicate tubular
vessels which pass into the three caudal appendages, and extend to
the end of each one, along the upper side. While the valves of the
heart, in all insects, are directed anteriorly because the blood
flows from behind, in the larva of the Ephemeridæ the valves of the
last chamber of the heart are directed backwards, because from this
chamber the blood flows in the opposite direction, _i.e._ into the
caudal appendages. During the contraction of the heart, the
elongated section of the same in the last abdominal segment receives
a part of the mass of blood contained in the last chamber, which is
driven by independent contractions into the caudal appendages. These
vessels have openings before the end through which the blood enters
into the cavity of the appendages, and can also pass back, in order
to be taken up by the body cavity. It is possible that these
blood-vessels stand in direct relation to respiration. (Zimmermann,
Creutzburg, in Kolbe, p. 544.)
=The pericardial cells.=—Along the heart, on both sides, occur the
so-called pericardial cells, which differ from the fat-cells, and
also the peritracheal cells of Frenzel, and are mostly arranged in
linear series, which have a close relation to the circulation of the
blood. In the larva of Chironomus, they lie in groups; in that of
Culex, they are arranged segmentally. In caterpillars, these
pericardial cells are not situated in the region of the heart, but
are arranged linearly on the side, and form a network of granulated
cells situated between the fat-bodies. Other rows of these cells are
situated near the stigmata and the main lateral tracheæ. (Kolbe.)
According to Kowalevsky, the pericardial cells, and the
garland-shaped, cellular cord consist of cells, whose function it is
to purify the blood, and to remove the foreign or injurious matters
mingled with the blood.
[Illustration:
FIG. 379.—Diagram of the circulatory organs in the head of the
cockroach, seen from above: _A_, ampulla; _V_, antennal vessel;
_M_, chief muscular cord; _m_, muscular band; _Bs_, wall of the
blood sinus; _am_, opening of the aorta (a); _rg_, anterior
sympathetic or visceral ganglion; _hg_, hinder visceral ganglion;
_F_, _F_, facetted eyes; _o_, vestigial ocellus; _G_, _G_, brain;
_S_, œsophagus.—After Pawlowa.
]
=Ampulla-like blood circulation in the head.=—In the head of the
cockroach occurs, according to Pawlowa, a contractile vascular sac
at the base of each antenna. The cavity has a valvular communication
with the blood space below and in front of the brain, and
muscle-fibres effect systole and diastole. Each sac is beyond doubt
an independently active part of the circulatory system. These organs
also occur in Locusta and other Acrydiidæ, and Selvatico has
described similar structures in _Bombyx mori_ and certain other
Lepidoptera.
=Pulsatile organs of the legs.=—Accessory to the circulation is a
special system of pulsatile organs in the three pairs of legs of
Nepidæ, generally situated in the tibia just below its articulation
with the femur, but in the fore legs of Ranatra, in the clasp-joint
or tarsus, just below its articulation with the tibia. First
observed by Behn (1835), Locy has studied the organ (Fig. 380) in
Corixa, Notonecta, Gerris, besides the Nepidæ. It is a whip-like
structure attached at both ends, with fibres extending upward and
backward to the integument of the leg, separate from the muscular
fibres and does not involve them in its motions, and is not affected
by the muscles themselves. “As the blood-corpuscles flow near the
pulsating body they move faster, and around the organ itself there
is a whirlpool of motion.” The beating of these organs aids the
circulation in both directions, and when the motion ceases, the
blood-currents in the legs stop; the rate of the pulsating organ is
always faster than that of the heart, and the action is automatic.
[Illustration:
FIG. 380.—Pulsating organs in Hemiptera: _A_, Belostoma nymph, _B_,
legs of Corixa. _C_, Ranatra, adult, to show the exceptional
position of the pulsating organ in the fore legs. _D_, pulsatile
organ in tibia of Ranatra.—After Locy.
]
_b._ The blood
The blood of insects, as in other invertebrates, differs from that of
the higher animals in having no red corpuscles. It is a thin fluid, a
mixture of blood (serum) and chyle, usually colorless, but sometimes
yellowish or reddish, which contains pale amœboid corpuscles
corresponding to the white corpuscles (leucocytes) of the vertebrates,
though they are relatively less numerous in the blood of insects. The
yellow fluid expelled from the joints of certain beetles (Coccinella,
Timarcha, and the Meloidæ) is, according to Leydig, only the serum of
the blood. In phytophagous insects the blood is colored greenish by the
chlorophyll set free during digestion. The blood of _Deilephila
euphorbia_ is colored an intense olive-green, and that of _Cossus
ligniperda_ is pale yellow. (Urech.) The blood of case-worms
(Trichoptera) is greenish. In some insects it is brownish or violet. The
serum is the principal bearer of the coloring material, yet Graber has
shown that in certain insects the corpuscles are more or less beset with
bright yellow or red fat-globules, so as to give the same hue to the
blood.
=The leucocytes.=—The corpuscles are usually elongated, oval, or
flattened oat-shaped, with a rounded nucleus, or are often amœbiform;
and they are occasionally seen undergoing self-division. When about to
die the corpuscles become amœbiform or star-shaped. (Cattaneo.) Their
number varies with the developmental stage of the insect, and in larvæ
increases as they grow, becoming most abundant shortly before pupation.
The blood diminishes in quantity in the pupal stage, and becomes still
less abundant in the imago. (Landois.) The quantity also varies with the
nutrition of the insect, and after a few days’ starvation nearly all the
blood is absorbed. Crystals may be obtained by evaporating a drop of the
blood without pressure; they form radiating clusters of pointed needles.
The freshly drawn blood is slightly alkaline. (Miall and Denny.)
The size of the corpuscles has been ascertained by Graber, who found
that the diameter of the circular blood-disks of the leaf-beetle,
_Lina populi_, is 0.006 mm.; of _Cetonia aurata_ and _Zabrus
gibbus_, 0.008 to 0.01 mm.; and those of certain Orthoptera
_(Decticus verrucivorus_, _Ephippiger vitium_ and _Œdipoda
cœrulescens_), 0.011 to 0.014 mm. The longest diameter of the
elongated corpuscles of _Carabus cancellatus_ is 0.008 mm.; of
_Gryllus campestris_, _Locusta viridissima_, _Cossus ligniperda_,
_Sphinx ligustri_ (pupa), and others, 0.008 to 0.01 mm.; of
_Caloptenus italicus_, _Saturnia pyri_, _Anax formosus_, and others,
0.011 to 0.014 mm.; of _Ephippiger vitium_, _Œdipoda cœrulescens_,
_Pezotettix mendax_, _Zabrus gibbus_, _Phryganea_, and others, 0.012
to 0.022 mm.; in _Stenobothrus donatus_ and _variabilis_, 0.012 to
0.035 mm. The largest known are those of _Melolontha vulgaris_,
which measure from 0.027 to 0.03 mm.
[Illustration:
FIG. 381.—Blood corpuscles, or leucocytes, of insects: _A_, _a-g_, of
_Stenobothrus dorsatus_ (the same forms occur in most Orthoptera and
in other insects). _B_, _a_, leucocyte of the same insect with the
nucleus brought out by ether; _b_, another of serpentine shape. _C_,
leucocytes of the same insect after a longer stay in ether. _D_,
leucocytes of the same after being in glycerine 14 days.—After
Graber.
]
As regards the nature of the corpuscles, Graber concludes that they are
more like the cells of the fat-bodies than genuine cells. That they are
not true cells is shown by the fact that after remaining in their normal
condition a long time they finally coalesce and form cords. After
shrivelling, or after the blood has been subjected to different kinds of
treatment, the nucleus is clearly brought out (Fig. 381).
Besides the blood corpuscles there have been detected in the blood round
bodies which are regarded as fat-cells. They are circular, and for the
most part larger than the blood corpuscles, have a sharp, even, dark
outline, and an invariably circular nucleus. (Kolbe.)
The blood of Meloe, besides the amœboid corpuscles, according to
Cuénot, contains abundant fibrinogen, which forms a clot; a pigment
(uranidine), which is oxidized and precipitated when exposed to the
air; a dissolved albuminoid (hæmoxanthine), which has both a
respiratory and nutritive function; and, finally, dissolved
cantharidine.
The corpuscles arise from tissues which are very similar to the
fat-bodies, and which, at given times, separate into cells. The
position of these tissues is not always the same in different
insects. In caterpillars, they occur in the thorax, near the germs
of the wings; in the saw-flies (Lyda), in all parts of the thorax
and abdomen; in larval flies (Musca), in the end of the abdomen,
just in front of the large terminal stigmata. The place where the
blood corpuscles are formed is usually near, or in relation with,
the fat-bodies. But while the fat-bodies mostly serve as the
material for the formation of the blood-building tissues, in
caterpillars the tracheal matrix also, and, in dipterous larvæ, the
hypodermis serve this purpose. (Cæsar Schaeffer in Kolbe. See also
Wielowiejski, Ueber das Blutgewebe.)
Other substances occur in the blood of insects. Landois (1864)
demonstrated the existence of egg albumen, globulin, fibrin, and
iron in the blood of caterpillars. Poulton found that the blood of
caterpillars often contained chlorophyll and xanthophyll derived
from their food plants. A. G. Mayer has recently found that the
blood (hæmolymph) of the pupæ of Saturniidæ (_Callosamia promethea_)
contains egg albumin, globulin, fibrin, xanthophyll, and
orthophosphoric acid, and Oenslager has determined that iron,
potassium, and sodium are also present. (Mayer.)
_c._ The circulation of the blood
Every part of the body and its appendages is bathed by the blood, which
circulates in the wings of insects freshly emerged from the nymph or
pupal state, and even courses through the scales of Lepidoptera, as
discovered by Jaeger (Isis, 1837).
In describing the mechanism of the heart we have already considered in a
general way the mode of circulation of the blood.
The heart pumping the blood into the aorta, the nutritive fluid passes
out and returns along each side of the body; distinct, smaller streams
passing into the antennæ, the legs, wings (of certain insects), and into
the abdominal appendages when they are present. All this may readily be
observed in transparent aquatic insects, such as larval Ephemeræ,
dragon-flies, etc., kept alive for the purpose under the microscope in
the animalcule box.
Carus, in 1827, first discovered the fact of a complete circulation of
the blood, in the larva of Ephemera. He saw the blood issuing in several
streams from the end of the aorta in the head and returning in currents
which entered the base of the antennæ and limbs in which it formed
loops, and then flowing into the abdomen, entered the posterior end of
the heart. Wagner (Isis, 1832) confirmed these observations, adding one
of his own, that the blood flows backward in two venous currents, one at
the sides of the body and intestine, and the other alongside of the
heart itself, and that the blood not only entered at the end of the
heart, but also at the sides of each segment, at the position of the
valves discovered by Straus-Dürckheim.
Newport maintains that the course of the blood is in any part of the
body, as well as in the wings, almost invariably in immediate connection
with the course of the tracheæ, for the reason that “the currents of
blood in the body of an insect are often in the vicinity of the great
tracheal vessels, both in their longitudinal and transverse direction
across the segments.”
The circulation of the blood in the wings directly after the exuviation
of the nymph or pupa skin, and before they become dry, has been proved
by several observers. As stated by Newport, the so-called “veins” or
“nervures” of the wings consist of tracheæ lying in a hollow cavity, the
peritracheal space being situated chiefly under and on each side of the
trachea.
[Illustration:
FIG. 382.—Circulation of the blood in hind wing of _Periplaneta
orientalis_: the arrows indicate the usual direction of the blood
currents.—After Moseley.
]
Newport gives the following summary of the observations of the early
observers, to which we add the observations of Moseley. “A motion of
the fluids has been seen by Carus in wings of recently developed
Libellulidæ, _Ephemera lutea_ and _E. marginata_, and _Chrysopa
perla_; among the Coleoptera, in the elytra and wings of _Lampyris
italica_ and _L. splendidula_, _Melolontha solstitialis_ and
Dytiscus.” Ehrenberg saw it in Mantis, and Wagner in the young of
_Nepa cinerea_ and _Cimex lectularius_. Carus detected a circulation
in the pupal wings of some Lepidoptera, and Bowerbank witnessed it
in a Noctuid (_Phlogophora meticulosa_); Burmeister observed it in
_Eristalis tenax_ and _E. nemorum_, and Mr. Tyrrel in _Musca
domestica_, but it has not been observed in the wings of
Hymenoptera.
Bowerbank observed that in the lower wing of _Chrysopa perla_ the
blood passes from the base of the wing along the costal,
post-costal, and externo-medial veins, outwards to the apex of the
wing, giving off smaller currents in its course, and that it returns
along the anal vein to the thorax. He found that the larger veins,
1⁄408 in. in diameter, contained tracheæ which only measured 1⁄2222
of an inch in diameter; but in others the tracheæ measured 1⁄1340,
while the cavity measured only 1⁄500 of an inch. He states, also,
that the tracheæ very rarely give off branches while passing along
the main veins, and that they lie along the canals in a tortuous
course. (Newport, art. Insecta, p. 980.)
Bowerbank, also, in his observations on the circulation in the wings
of Chrysopa, “used every endeavor to discover, if possible, whether
the blood has proper vessels, or only occupied the internal cavities
of the canals; and that he is convinced that the latter is the case,
as he could frequently perceive the particles not only surrounding
all parts of the tracheæ, and occupying the whole of the internal
diameter of the canals, but that it frequently happens that globules
experienced a momentary stoppage in their progress, occasioned by
their friction against the curved surface of the tracheæ, which
sometimes gave them a rotatory motion.”
[Illustration:
FIG. 383.—Parts of a vein of the cockroach, showing the nerve (_n_)
by the side of the trachea (_tr_); _c_, blood corpuscles.—After
Moseley.
]
Moseley found, owing to the large size and number of the corpuscles,
that the circulation of the blood in the wings of insects is most
easily observed in the cockroach, especially the hind wings. As seen
in Moseley’s figure, the blood flows outward from the body through
the larger veins (I and II) of the front edge of the wings, which he
calls the main arteries of the wings, and more generally returns to
the body through the veins in the middle of the wing; the blood also
flows out from the body through the inner longitudinal veins (those
behind vein IV), and the blood is also seen to flow through some of
the small cross-veins. Fig. 383 shows one of the main trunks during
active circulation. The corpuscles change their form readily, “the
spindle-shaped ones doubling up in order to pass crossways through a
narrow aperture.... In the irregularly formed corpuscles, which seem
to represent leucocytes amœboid movements were observed....
Corpuscles pass freely above and under the tracheæ, showing that
these latter lie free in the vessels.” The hypodermis lining the
vessels is best seen in the small transverse veins.
The pulse or heart-beat of insects varies in rapidity in different
insects, rising at times of excitement, as Newport noticed in
_Anthophora retusa_, to 142 beats in a minute.
When an insect, as, for example, a tineid caterpillar, has been enclosed
in a tight box for a day or more, the pulsations of the heart are very
languid and slow, but soon, on giving it air, the pulsations will, as we
have observed, rise in frequency to about 60 a minute, Herold observed
30 to 40 in a minute in a fully-grown silkworm, and from 46 to 48 in a
much younger one. Suckow observed but 30 a minute in a full-grown
caterpillar of _Gastropacha pini_, and 18 only in its pupa.
In a series of observations made by Newport on _Sphinx ligustri_
from the fourth day after hatching from the egg until the perfect
insect was developed, he found that before the larva cast its first
skin the mean number of pulsations, in a state of moderate activity
and quietude, was about 82 or 83 a minute; before the second moult
89, while before the third casting it had sunk down to 63; and
before its fourth to 45, while, before leaving its fourth stage, and
before it had ceased to feed, preparatory to pupating, the pulse was
not more than 39. “Thus the number gradually decreases during the
growing larva state, but the force of the circulation is very much
augmented. Now when the insect is in a state of perfect rest,
previously to changing its skin, the number is pretty nearly equal
at each period, being about 30. When the insect has passed into the
pupa state it sinks down to 22, and subsequently to 10 or 12, and
after that, during the period of hibernation, it almost entirely
ceases. But when the same insect which we had watched from its
earliest condition was developed into the perfect state in May of
the following spring, the number of pulsations, after the insect had
been for some time excited in flight around the room, amounted to
from 110 to 139; and when the same insect was in a state of repose,
to from 41 to 50. When, however, the great business of life, the
continuation of the species, has been accomplished, or when the
insect is exhausted, and perishing through want of food or other
causes, the number of pulsations gradually diminishes, until the
motions of the heart are almost imperceptible.” Insects, then, he
remarks, do not deviate from other animals in regard to their vital
phenomena, though it has been wrongly imagined that the nutrient and
circulatory functions are less active in the perfect than in the
larval condition.
The heart of a larval _Gastrus equi_ taken the day previous from a
horse’s stomach beat from 40 to 44 times a minute (Scheiber); while
Schröder van der Kolk observed only 30 beats in the same kind of
maggot.
In the larva of Corethra, while at rest, the heart contracts from 12
to 16 or 18 times a minute, but when active the number rises to 22.
The systole and diastole last from 5 to 6 minutes. (Dogiel.)
Temperature also affects the pulsations, as they increase in
frequency with a rise and decrease with a fall in temperature.
=Influence of electricity.=—The influence of electricity on the
action of the insect’s heart, from Dogiel’s experiments, is such as
to cause an acceleration in the frequency of the beats, while an
increase in the strength of the electric currents either diminishes
the frequency of the beats or entirely stops the heart’s action. A
violent excitation with the induction current causes a systole when
the heart’s action has stopped for a long time; and if the
excitation lasts uninterruptedly, then the contractions after a
while become noticeable, according to the strength of the current.
In such a case there are, however, interruptions in the regularity,
strength, and order of the contractions. (Kolbe.)
=Effects of poisons on the pulsations.=—Dogiel has also experimented
on the influence of poisons in the form of vapor or as liquid
solutions on the pulsations of insects, which is much as in
vertebrates. The application of carbonic oxide to the larva of
Corethra, whose heart one minute previous to the poisoning beat 15
times a minute, accelerated the heart-beats in about 55 minutes to
25 pulsations in a minute. Afterwards there was a retardation in the
pulse to the normal beat. Carbonic acid had a similar effect.
The following results obtained by Dogiel are somewhat as tabulated by
Kolbe:—
I. Substances which cause the pulsations of the heart to accelerate.
_a._ An induction current of electricity, acting feebly.
_b._ Ammonia, acting feebly.
_c._ Ethyl ether, acting feebly.
_d._ Oxalic acid, acting feebly.
_e._ Carbolic acid, acting feebly.
_f._ Potassium nitrate, acting feebly.
_g._ Aconite, acting feebly.
II. Substances retarding the heart’s action.
_a._ An induction current of electricity, acting energetically.
_b._ Ammonia, acting energetically.
_c._ Ethyl ether, acting energetically.
_d._ Oxalic acid, acting energetically.
_e._ Carbolic acid, acting energetically.
_f._ Veratrine, acting energetically.
_g._ Atropine, acting energetically.
_h._ Aconitine, acting energetically.
_i._ Potassium nitrate, acting energetically.
_g._ Ethyl alcohol.
_h._ Chloroform.
_i._ Carbonic oxide.
_j._ Carbonic acid.
_k._ Sulphuretted hydrogen.
III. Substances whose action is indifferent.
_1._ Muscarine.
_2._ Curare.
_3._ Atropine, acting slowly.
_4._ Strychnine.
The above-named substances comprise those which in the vertebrates
effect a change in the activity of the motor nerve-ganglia of the
heart and the muscular fibres. Hence it follows that the heart of
the larval Corethra consists of muscular fibres provided with
ganglia, and that the contractions of the muscular fibres are
provoked through the agency of the ganglia. But since muscarine,
atropine, and curare, whose influence in stopping the heart’s action
of vertebrates is known, in insects either have no action or only
make the pulsations slower; it seems to follow that the heart of the
larval Corethra possesses no similar apparatus for lessening the
heart’s action, and this is also confirmed by anatomical studies. On
the contrary, aconite acts, as we must from observations conclude,
exclusively on the motor centres and the muscles, but not on the
apparatus for lessening the heart’s action, which, as has been
remarked, is not present in the larval Corethra. (Kolbe _ex_
Dogiel.)
Dewitz has discovered an onward movement of the blood corpuscles,
somewhat independent of the general circulation. This independent
motion of the blood corpuscles is not only a creeping one like the
amœboid motion of the white corpuscles of vertebrates, but they have
besides a peculiar swimming movement. Dewitz noticed this in the
hind wings of a recently emerged meal-worm beetle (_Tenebrio
molitor_), still white and soft, after they had been cut off. The
tissues forming the matrix within the wings constitute a network
filled with blood. The current of blood within the wing thus cut off
may be stopped flowing by a tap on the firmly clamped object-bearer
on which the wing is placed, or by drawing it by an apparatus
described by the same author, to incite in one way or another the
blood corpuscles to swim forwards. When a corpuscle is disposed to
move, we see it first stirring restlessly, or wabbling about, in
this way changing its form; then it moves forwards, and does not
come to a standstill. If it remains still there, after a while, by
tapping, it begins again its movements.
“Should one yet doubt the fact of this spontaneous movement of the
blood corpuscles, he will surely be convinced of its correctness by
observing the so-to-speak reluctantly springing motion of a blood
corpuscle in the wing of _Tenebrio molitor_ with the simultaneous
change of appearance and shape of the corpuscle.”
This spontaneous or independent motion of the blood corpuscles is
also produced by the heating apparatus. As soon as the corpuscles
lie still in the severed wing and they are warmed, the corpuscles
begin to pass through the meshes of the tissue. When cooled, the
motion ceases, but as soon as the temperature rises to a certain
grade, the corpuscles again move onwards.
To explain this independent motion Dewitz thinks that they take up
and then expel the blood-fluid, and in this way cause their motion.
This independent motion is necessitated, in order that the stream of
blood may become so regulated, that the blood corpuscles shall not
be arrested in their course, but even turn back again out of the
farther end of the antennæ and limbs. The chief mechanical power for
the blood circulation must go on independently of the propulsatorial
apparatus and of the heart. (Kolbe.)
LITERATURE ON THE HEART AND ON THE CIRCULATION OF THE BLOOD
_a._ Anatomy of the organs
=Meckel, J. F.= Ueber das Rückengefäss der Insekten. (Meckel’s Archiv,
i, 1815, pp. 469–476.)
=Müller, J. G.= De vasi dorsali Insectorum. Berolini, 1816, pp. 22.
=Serres, P. Marcel de.= Observations sur les usages du vaisseau dorsal
ou sur l’influence que le cœur exerce dans l’organisation des
animaux articulés, etc. (Ann. du Mus. d’hist. nat., 1818, iv, pp.
149–192, 313–380, 2 Pls.; v, 1819, pp. 59–147, 1 Pl.)
=Herold.= Physiologische Untersuchungen über das Rückengefäss der
Insekten. (Schriften d. Gesellsch. z. Beförderung d. Naturk. in
Marburg, 1823, i, pp. 41–107.)
=Carus, C. G.= Entdeckung eines einfachen vom Herzen aus
beschleunigten Blutkreislaufes in den Larven netzilügliger Insekten.
Leipzig, 1827, pp. 40, 3 Taf.
—— Fernere Untersuchungen über Blutlauf in Kerfen. (Acta Acad.
Leopold. Carol., 1831, xv, pp. 1–18, 1 Taf.)
=Stadelmayr, L.= Ansichten vom Blutlauf nebst Beobachtungen über das
Rückengefäss der Insekten. Diss. München, 1829, pp. 24.
=Berthold.= Beitrage zur Anatomie, Zoologie und Physiologie.
Göttingen, 1831.
=Treviranus, G. R.= Ueber das Herz der Insekten, dessen Verbindung mit
den Eierstocken und ein Bauchgefäss der Lepidopteren. (Zeitschr. f.
d. Physiologie, von F. Tiedemann. G. R. u. L. C. Treviranus, 1832,
iv, pp. 181–184, 1 Taf.)
—— Beobachtungen aus der Zootomie und Physiologie. Bremen, 1839.
=Wagner, R.= Beobachtungen über Kreislauf des Blutes und den Bau des
Rückengefässes bei den Insekten. (Isis, 1832, iii, p. 30; vii, pp.
320–331, 778–783, Fig.)
=Bowerbank, J. S.= Observations on the circulation of the blood in
insects. (Ent. Mag., 1833, i, pp. 239–244, 1 Pl; also in Müller’s
Archiv f. Physiolog., 1834, i, pp. 119–120.)
—— Observations on the circulation of the blood and the distribution
of the tracheæ in the wing of _Chrysopa perla_. (Ent. Mag., 1837,
iv, pp. 179–185.)
=Jaeger.= Ueber die Entdeckung von einer Bewegung in den Schuppen des
Schmetterlingsflügel. (Isis, 1837, v, p. 512.)
=Behn, W.= Découverte d’une circulation de fluide nutritif dans les
pattes de plusieurs insectes hémipteres. (Ann. Sc. nat., 1835, Sér.
2, iv, pp. 1–12.)
=Newport, G.= Insecta, in Todd’s Cyclopædia of Anatomy and Physiology,
1839. London, pp. 853–994. On the circulation of the blood, p. 976,
Figs.
=Duvernoy, G. L.= Résumé sur le fluide nourricier, ses réservoirs et
son mouvement dans tout règne animal. (Ann. Sc. nat., 1839, Sér. 2,
xii, pp. 300–346.)
=Dufour, L.= Études anatomiques et physiologiques sur une mouche dans
le but d’eclairer l’histoire des metamorphoses et de la prétendue
circulation dans les insectes. (Ann. Sc. nat. Zool., Sér. 2, 1841,
xvi, pp. 5–14.)
—— Note sur la prétendus circulation dans les insectes. (Compt. rend.
Acad., Paris, 1844, xix, pp. 188–189.)
—— Études anatomiques et physiologiques sur une mouche, dans le but
d’éclaircir l’histoire des metamorphoses et de prétendue circulation
des insectes. (Mém. mathémat. des Savants étrangers, Paris, 1846,
ix, pp. 545–628, 1 Pl.)
—— Sur la circulation dans les insectes. Bordeaux, 1849, 8º, pp. 40.
(Compt. rend. Acad. Sci., Paris, 1849, xxviii, pp. 28–33, 101–104,
163–170.)
—— De la circulation du sang et de la nutrition chez les insectes.
Bordeaux, 1851. (Act. Soc. Linn., Bordeaux, 1851, xvii, p. 9.)
—— Études anatomiques et physiologiques et observations sur les larves
des Libellules, Appareil circulatoire. (Annal. Sci. nat., Sér. 3,
Zool., xvii, 1852, pp. 98–101, 1 Pl.)
=Schröder van der Kolk, J. S. C.= Mémoire sur l’anatomie et
physiologie du _Gastrus equi_. (N. Verhandl. Kl. Nederl. Instit.,
11, 1845, pp. 1–155, 13 Pl.)
=Nicolet, H.= Note sur la circulation du sang chez les Coléoptères.
(Ann. Sc. nat., 1847, Sér. 3, vii, pp. 60–64.)
=Verloren, C.= Mémoire en réponse à la question suivante: éclaircir
par des observations nouvelles le phénomène de la circulation dans
les insectes, en recherchant si on peut la reconnaître dans les
larves de différents ordres de ces animaux. (Mém. couronn. et Mém.
d. savants étrang. de l’Acad. Roy. Belgique, xix, 1847.)
=Blanchard, E.= De la circulation dans les insectes. (Ann. Sc. nat.,
1848, Sér. 3, ix, pp. 359–398, 5 Pls.)
—— Sur la circulation du sang chez les insectes et sur la nutrition.
(Compt. rend. Acad. Sc., Paris, 1849, xxviii, pp. 76–78; 1851,
xxxiii, pp. 367–370.)
—— Nouvelles observations sur la circulation du sang et la nutrition
chez les insectes. (Ibid., pp. 371–376.)
=Joly, N.= Mémoire sur l’existence supposée d’une circulation
péritrachéenne chez les insectes. (Ann. Sc. nat. Zool., Sér. 3,
1849, xii, pp. 306–316.)
=Bassi, C. A.= Rapporto alla sezione di zoologia, anatomia comparata e
fisiologia del congresso di Venezia, sul passagio delle materie
ingerite nel sistema tracheale degli insetti. (Gazette di Milano,
1847, vi; also Ann. Sc. nat. Zool., Sér. 3, 1851, xv., 362–371.)
=Agassiz, Louis.= On the circulation of the fluids in insects.
(Proceed. Amer. Assoc. Adv. Sc., 1849, pp. 140–143; Ann. Sc. nat.
Zool., Sér. 3, xv, 1851, pp. 358–362.)
=Leydig, F.= Anatomisches und Histiologisches über die Larve von
_Corethra plumicornis_. (Zeitschr. f. wissen. Zool., iii, 1851, pp.
435–451.)
=Wedl, C.= Ueber das Herz von _Menopon pallidum_. (Sitzungsber. der k.
Akad. d. Wissensch. Wien., 1855, xvii, pp. 173–180.)
=Scheiber, S. H.= Vergleichende Anatomie und Physiologie der Oestriden
Larven. (Sitzungsber. d. k. Akad. d. Wiss. Wien. Math.-naturwiss.
Cl., xli, 1860, pp. 409–496, 2 Taf.; The circulatory system, pp.
463–490.)
=Brauer, Fr.= Beitrag zur Kenntnis des Baues und der Funktion der
Stigmenplatten der Gastrus-Larven. (Verhdl. d. k. k. zool.-bot.
Gesellsch. Wien., xiii, 1863, pp. 133–136.)
=Moseley, H. N.= On the circulation in the wings of _Blatta
orientalis_ and other insects, and on a new method of injecting the
vessels of insects. (Quart. Jour. of Micr. Science, xi, n. s., pp.
389–395, 1871, 1 P1.)
=Graber, V.= Ueber die Blatkörperchen der Insekten. (Sitzber. Akad.
Wien. Math.-naturw. Classe, lxiv, 1871, pp. 9–44, 1 Taf.)
—— Vorläufiger Bericht über den propulsatorischen Apparat der
Insekten. (Sitzber. d. k. Ak. d. Wiss. Wien., lxv, 1872, pp. 16, 1
Taf.)
—— Ueber den propulsatorischen Apparat der Insekten. (Archiv f.
mikroskop. Anatomie, ix, 1873, pp. 129–196, 3 Taf.)
—— Ueber den pulsierenden Bauchsinus der Insekten. (Archiv f.
mikroskop. Anat., xii, 1876, pp. 575–582, 1 Taf.)
=Grobben, Carl.= Über bläschenförmige Sinnesorgane und eine
eigenthümliche Herzbildung der Larve von _Ptychoptera contaminata_
L. (Sitzb. k. Akad. Wissensch. Wien., 1875, lxxii, p. 22, 1 Taf.)
=Liebe, Otto.= Ueber die Respiration der Tracheaten, besonders über
den Mechanismus derselben und über die Menge der ausgeatmeten
Kohlensäure. Inaug.-Diss. Chemnitz, 1872, pp. 28.
=Dogiel, John.= Anatomie und Physiologie des Herzens der Larve von
_Corethra plumicornis_. (Mém. Acad. imp. St. Petersbourg, 7 Sér.,
xxiv, 1877, Nr. 10, pp. 37, 2 Pls.) Separate, Leipzig, Voss.
=Bütschli, O.= Ein Beitrag zur Kenntnis des Stoffwechsels,
insbesondere der Respiration bei den Insekten. (Reichert’s und Du
Bois-Reymond’s Archiv f. Anatomie u. Physiologie, 1874, pp.
348–361.)
=Béla-Dezso.= Ueber den Zusammenhang des Kreislaufs und der
respiratorischen Organe bei den Arthropoden. (Zool. Anzeiger, i
Jahrg., 1878, p. 274.)
=Plateau, F.= Communication préliminaire sur les mouvements et
l’innervation de l’organe central de la circulation chez les animaux
articulés. (Bull. Acad. roy. de Belgique, Sér. 2, xlvi, 1878, pp.
203–212.)
=Jaworovski, Ant.= Ueber die Entwicklung des Rückengefässes und
speziell der Muskulatur bei Chironomus und einigen anderen Insekten.
(Sitzgsber. d. k. Akad. d. Wissensch. Wien. Math.-naturwiss. Cl.,
lxxx, 1879, pp. 238–258.)
=Zimmermann, O.= Ueber eine eigentümliche Bildung des Rückengefässes
bei einigen Ephemeridenlarven. (Zeitschr. f. wissens. Zool., 1880,
xxxiv, pp. 404–406.)
=Burgess, E.= Note on the aorta in lepidopterous insects. (Proc. Bost.
Soc. Nat. Hist., xxi, 1881, pp. 153–156, Figs.)
—— Contributions to the anatomy of the milk-weed butterfly, _Danais
Archippus_ F. (Anniversary Memoirs Boston Soc. Nat. Hist., 1880, pp.
16, 2 Pls.)
=Vayssière, A.= Recherches sur l’organisation des larves des
Éphémérines. (Ann. Sc. nat. Zool., Sér. 6, xiii, 1882, pp. 1–137, 11
Pls.)
=Viallanes, H.= Recherches sur l’histologie des insectes et sur les
phénomènes histologiques qui accompagnent le développement
post-embryonnaire de ces animaux. (Ann. Sc. nat., Sér. 6, xiv, 1882,
pp. 1–348, 18 Pls.)
=Schimkewitsch, W.= Ueber die Identität der Herzbildung bei den wirbel
und wirbellosen Tieren. (Zool. Anzeiger, 1885, viii Jahrg., pp.
37–40, Fig.)
—— Noch etwas über die Identität der Herzbildung bei den Metazoen.
(Zool. Anzeiger, 1885, pp. 384–386.)
=Creutzburg, N.= Ueber den Kreislauf der Ephemerenlarven. (Zool.
Anzeiger, 1885, pp. 246–248.)
=Poletajewa, Olga.= Du cœur des insectes. (Zool. Anzeiger, 1886, ix
Jahrg., pp. 13–15.)
=Selvatico, S.= L’aorta nel corsaletto e nel capo della farfalla del
bombice del gelso. (Padova, 1887, p. 19, 2 Pls.)
—— Die Aorta im Brustkasten und im Kopfe des Schmetterlings von
_Bombyx mori_. (Zool. Anzeiger, 1887, x Jahrg., pp. 562–563.)
=Kowalevsky, A.= Ein Beitrag zur Kenntnis der Excretionsorgane. (Biol.
Centralbl., 1889, ix, pp. 33–47, 65–76, 127–128.)
=Tosi, Alessandro.= Osservazioni sulla valvola del cardias in varii
generi della famiglia delle Apidi. (Ricerche Lab. Anat. R. Univ.
Roma, v, 1895, pp. 5–26, 16 Figs., 3 Pls.)
=Pawlowa, Mary.= Ueber ampullenartige Blutcirculationsorgane im Kopfe
verschiedener Orthopteren. (Zool. Anzeiger, xviii Jahrg., 1895, pp.
7–13, 1 Fig.)
Also the writings of Kolbe.
_b._ The blood, blood corpuscles, leucocytes, and blood tissue
=Wagner, R.= Ueber Blutkörperchen bei Regenwürmern, Blutegeln und
Dipterenlarven. (Müller’s Archiv f. Anatomie u. Physiologie, 1835,
pp. 311–313.)
—— Nachtrage zur vergleichenden Physiologie des Blutes. (Archiv f.
Anat. u. Physiologie, 1838.)
=Newport, G.= On the structure and development of the blood. First
series. The development of the blood corpuscle in insects and other
invertebrata, and its comparison with that of man and the
vertebrata. (Abstr. of the paper in Roy. Soc., 1845, v, pp. 544–546:
also in Ann. Mag. Nat. Hist., Ser. 3, 1845, iii, pp. 364–367.)
=Landois, H.= Beobachtungen über das Blut der Insekten. (Zeitschr. f.
wissens. Zool., xiv, 1864, pp. 55–70, 3 Pl.)
——, =and L. Landois.= Ueber die numerische Entwicklung der
histiologischen Elemente d. Insektenkörpers. (Ibid., xv, 1865, pp.
307–327.)
=Rollett, A.= Zur Kenntnis der Verbreitung des Hämatins. (Sitzgsber.
d. k. Akad. d. Wiss. Wien., lxiv, 1871.)
=Wielowiejski, H. v.= Ueber das Blutgewebe der Insekten. Eine
vorläufige Mitteilung. (Zeitschr. f. wissens. Zool., 1886, xliii,
pp. 512–536.)
=MacMunn, C. A.= Researches on myohæmatin and the histohæmatins.
(Proc. Roy. Soc. London, 1886, xxxix, pp. 248–252.)
=Peyron, J.= Sur l’atmosphere interne des insectes comparée à celle
des feuilles. (Compt. rend. Acad. Sc., Paris, 1886, cii, pp.
1339–1341.)
=Cuénot, L.= Études sur le sang, son rôle et sa formation dans la
série animale. Part 2, invertébrés; note préliminaire. (Arch. Zool.
Expériment., 1888, Sér. 2, v, pp. xliii-xlvii. See also ibid., Sér.
3, 1897, pp. 655, 679–680.)
=Dewitz, H.= Die selbstandige Fortbewegung der Blutkörperchen der
Gliedertiere. (Naturwiss. Rundschau. Braunschweig, 1889, iv Jahrg.,
pp. 221–222.)
—— Eigenthätige Schwimmbewegung der Blutkörperchen der Gliedertiere.
(Zool. Anzeiger, 1889, xii Jahrg., pp. 457–464, Fig.)
=Schäffer, C.= Beitrage zur Histiologie der Insekten. II, Ueber
Blutbildungsherde bei Insektenlarven. (Spengel’s Zool. Jahrbücher
Abt. f. Anat. u. Ontogenie, iii, 1889, pp. 626–636, 1 Taf.)
=Cattaneo, G.= Sulla morfologia delle cellule ameboidi dei Molluschi e
Artropodi. (Boll. Sc. Pavia. Anno 11, 1889, p. 59, 2 Pls.)
=Wagner, W. A.= Ueber die Form der körperlichen Elemente des Blutes
bei Arthropoden, Würmern und Echinodermen. (Biolog. Centralblatt,
1890, x, p. 428.)
=Preyer, W.= Zur Physiologie des Protoplasma. II, Die Funktionen des
Stoffwechsels. Die Saftströmung. (Patanie’s Naturwiss. Wochenschr.,
1891, vi, pp. 1–5.)
=Cholodkowsky, N.= Ueber das Bluten der Cimbiciden-Larven.
(Entomologische Miscellen, vi, Horæ Soc. Ent. St. Petersburg, 1897,
pp. 352–357, 1 Fig. The fluid thrown out through pores or fissures
in the skin is the blood.)
With the writings of Korotaiev, Tichomeroff, Pékarsky, Balbiani,
Korotneff, Cuénot, and others.
_c._ The fat-bodies
=Dufour, L.= Recherches anatomiques sur les Carabiques et sur
plusieurs autres insectes Coléoptères. Du tissu adipeux
splanchnique. (Ann. Sc. nat., viii, 1826, pp. 29–35.)
—— Histoire comparative des métamorphoses et de l’anatomie des
_Cetonia aurata_ et _Dorcus parallelepipedus_. Tissu adipeux
splanchnique. (Ann. Sc. nat., Zoologie, Sér. 2, 1842, xviii, pp.
178–179.)
=Meyer, H.= Ueber die Entwicklung des Fettkörpers, der Tracheen und
der keimbereitenden Geschlechtsteile bei den Lepidopteren.
(Zeitschr. f. wissens. Zool., 1849, i, pp. 175–179, 4 Taf.)
=Fabre, J. H.= Étude sur le rôle du tissu adipeux dans la sécretion
urinaire chez les insectes. (Ann. Sc. nat., Sér. 4, xix, 1862, pp.
351–382.)
=Leydig, Fr.= Einige Worte über Fettkörper der Arthropoden. (Reichert,
u. du Bois-Reymond’s Archiv f. Anat., 1863, pp. 192–203.)
=Lindemann, K.= Zoologische Skizzen. 1. Struktur des Fettkörpers.
(Bull. Soc. Imp. d. Natural. Moscou, 1864, pp. 521–526, 1 Pl.)
=Landois, Leonh.= Ueber die Funktion des Fettkörpers. (Zeitschr. f.
wissens. Zoologie, xv, 1865, pp. 371–372.)
=Wielowiejski, H. v.= Ueber den Fettkörper von _Corethra plumicornis_
und seine Entwicklung. (Zool. Anzeiger, 1883, vi Jahrg., pp.
318–322.)
—— Ueber das Blutgewebe der Insekten. (Zeitschr. f. wissens. Zool.,
1886, xliii, pp. 512–536.)
=Kowalevsky, A. O.= Sur les organes excréteurs chez les arthropodes
terrestres. (Congrès internat. Zool., 2^{me} Sess., pp. 196–205,
Moscou, 1892.)
THE BLOOD TISSUE
Under this name Wielowiejski has included several important tissues or
cellular bodies intimately concerned with the nutrition of the insect.
These are:—
1. The blood corpuscles. (See p. 407, leucocytes and phagocytes.)
2. The fat-body proper (_Corpus adiposum_).
3. The pericardial fat-body (pericardial cells).
4. The œnocytes.
5. The garland-shaped cord of muscid larvæ.
6. The subœsophageal body, a peculiar organ found by Wheeler in the
embryos and young larvæ of Blatta and Xiphidium.
7. The phosphorescent organs.
_a._ The fat-body
In the body cavity of winged insects and of their larvæ occur yellowish
masses of large cells filled with small drops of fat, and forming the
“fat-body.” It is of various shapes, more or less lobulated or net-like,
and covers or envelops parts of the viscera, also forming a layer under
the integument (Fig. 143). The tracheal endings are usually enveloped by
the fat-body. It is larger in the larvæ than in the adults, especially
in Lepidoptera, in them forming a reserve of nutrition, used during
metamorphosis and during the formation and ripening of the eggs and male
cells.
Wielowiejski has shown that there is a regular arrangement of the
fat-body in the general cavity of the body. For example, in the
larva of Chironomus occur the following forms of this tissue. Around
the periphery, on each side of the body cavity, is a loose network
of lobes with large meshes constituting the peripheral layer or
external lobular fat-body; these lobular masses are segmentally
arranged.
Within these segmental lobes, on each side of and along the
digestive tract, extending along through almost the entire body, is
an unbroken strand of this tissue, forming the internal fat-body
cords. From the first larval stage, and even before hatching, its
cells are so unusually large, being filled with large, clear, mostly
colorless fat-drops, that their limits cannot be defined, and their
nuclei can only with great difficulty be detected. Only in some
large larvæ of Chironomus has Wielowiejski found clearly defined
cells; the protoplasm of these cells contain almost no fat-drops.
The fat-body is of mesodermal origin, and as Wheeler insists, is not
derived from the œnocytes, as supposed by Graber. Formed from the
mesoderm, it is a differentiation of portions of the cœlomic walls,
and therefore metameric in origin. That the fat-body gives origin to
the blood corpuscles Wheeler is doubtful.
The fat-cells are distinct, spherical, and as a rule possess only
one nucleus, though in those of Apis and Melophagus there are two
nuclei, and in Musca several. Sometimes the cells contain a
substance like the white of an egg, and concretions of uric acid, or
these take the place of the fat-drops. The presence of uric acid
shows that a very active metabolism goes on in the fat-body. “In
some cases it has been proved that the fat-body in the larva is rich
in fat and poor in concretions of uric acid, while in the imago it
is poor in fat and rich in concretions of uric acid” (Lang).
Leydig, in 1857 (Lehrbuch der Histiologie), spoke of the presence of
dark concretions in the fat-body, and afterwards (1864) showed that
there was a wide distribution of uric acid salts and concretions.
Witlaczil, also, has detected concretions in the fat-body of the
Psyllidæ, in larval Cecidomyiidæ, in the larvæ and pupæ of ants, and
in the pupa of Musca.
The physiological processes which take place in the fat-bodies are
obscure. Graber regarded the whole system of the fat-bodies as “a
single, many-lobed lung,” while before him Landois, taking into
account the intimate relation existing between the finer tracheal
branches and the fat-body, considered that the latter was concerned
in respiration. Marchal thinks that the fat-body is a urinary organ,
as the urates are formed within the cells of this body.
Moreover, Schäffer maintains that a special kind of fat-body cell
has the important function of taking up and giving out nutritious
matters during the internal processes of metamorphosis, while he
also believes that there is a genetic connection between the
fat-body and the blood corpuscles—a view combated by Wheeler.
Kowalevsky finds that the fat-body remains absolutely insensible to
the action of the substances which stained the Malpighian tubes (p.
352). So long as the cells are healthy and living they are not
stained and do not absorb the colors in question; and this
insensibility persists, even when the cells are of a different
nature, as those of the fly (adipose and “intercalary” cells).
_b._ The pericardial fat-body or pericardial cells
We have already, on p. 405, called attention to these organs, but they
also have an intimate relation to the fat-body.
Kowalevsky (1892) remarks that the disposition of these cells varies
much in different insects and even in the same animal. Thus, in the
Diptera and the ordinary flies there are found around the lower part of
the dorsal vessel 13 pairs of large pericardial cells which lie next to
a crowded bed of small cells forming a compact mass around the anterior
part of the dorsal vessel. In caterpillars, notably silkworms, from the
compact layer of pericardial cells which surround the heart, pass off
trunks which are directed towards the lateral walls of the body, also
forming close networks around the tracheæ and then passing down into the
abdominal cavity of the body of the larva.
In the larvæ of certain Hymenoptera, the trunks which pass off from the
pericardial region form a loose cord, a sort of fatty tissue covering
the entire body cavity.
This tissue, adds Kowalevsky, entirely differs from œnocytes, or
from the so-called glandular body whose formation in Gryllotalpa has
been described by Korotaiev, and in _Bombyx mori_ by Tichomiroff. In
a recent work wherein has been collected everything known regarding
these last-named cells, Pékarsky proves that they are unique in
nature and cannot be regarded either as fat-cells, or as pericardial
cells, or even as formative leucocytes.
As to the structure of the pericardial cells, Kowalevsky adds that they
are always attached to muscular fibres passing off from the heart, and
that they lie, so to speak, upon them. In the locusts the muscular
fibres supporting the pericardial cells appear distinctly like little
staves or sticks. The attachment of the pericardial cells to the
muscular fibres has been observed by Cuénot and reproduced by him in his
work, but his description somewhat differs from that observed by
Kowalevsky in the locust (_Acrydium migratorium_).
As to the nature of the acid excretions which are formed in the
pericardial cells, in spite of his attempts to solve the problem,
Kowalevsky has been unsuccessful. The only observations in this
direction are those of Letellier on the pericardial glands of
lamellibranch molluscs, which he found to contain hypouric acid, and
it is probable, says Kowalevsky, that the acidity of the pericardial
cells in insects is due to the presence of the same acid.
=Leucocytes or phagocytes in connection with the pericardial cells.=—It
is thought by Schäffer that the leucocytes or phagocytes may be free or
wandering fat-body cells. They play an important part in metamorphosis,
while they absorb or feed upon the remains of the larval organs, and
thus prove of use in the building up of the organs of the adult insects.
While the faculty of _phagocytosis_ is wanting in the urinary tubes,
Balbiani and more recently Cuénot have expressed the opinion that the
pericardial cells of insects may have the power of absorbing hard
bodies, “acting as a phagocytic gland.” This, however, is called in
question by Kowalevsky, from studies made on different insects. On
introducing powdered carmine into the body of an insect it has not been
absorbed by the pericardial cells, as they have not been colored red. It
is the leucocytes which absorb the grains of carmine, and which, after
having dissolved them, transmit them to the pericardial cells. Hence,
then, the pericardial cells have not the phagocytic power of which
Cuénot speaks.
Returning to his own observations on hard bodies introduced into
insects, or large globules introduced under the form of a milk emulsion,
Kowalevsky has found that these bodies were absorbed in the first place
by the free-swimming leucocytes, and in the second place by whole groups
or nests of leucocytes situated in different parts of the body,
principally on the threads of the adipose body. In the Orthoptera the
absorption is immediately effected by means of the cells of the membrane
which separates the pericardium from the cavity of the body underneath
the heart. The regions where the hard bodies are absorbed in great
number coincide with the regions of formation of the blood corpuscles.
In his researches on the larvæ of Hyponomeuta and other Lepidoptera,
Schäffer describes these regions as forming a sort of island. The nests
where the blood globules are formed are the most active centres of
phagocytosis.
[Illustration:
FIG. 384.-Section of the heart (_c_) and pericardial cells (_pc_,
_pc_) from the posterior part of the heart of a fly: _l_, _l_, nests
of leucocytes situated between the heart and pericardial cells.—From
a microphotograph, after Kowalevsky.
]
[Illustration:
FIG. 385.—Cross-section of the heart of _Truxalis nasata_ and of the
structures around it: _c_, heart: _ep_, epithelium under the
cuticula (hvpodermis); _or_, ovarian tubes; _pc_, pericardial cells,
with one or two nuclei containing a deposit of carmine; _l_ and
_l′_, group of leucocytes, which have absorbed granules of India
ink.—After Kowalevsky.
]
Balbiani, and also Cuénot, have supposed that the formation of the
blood corpuscles takes place in the pericardial cells, but
Kowalevsky insists that these cells cannot form the leucocytes,
which “are probably formed in different parts of the body, notably
in the special nests [_Herde_ of Jäger] situated near the heart, but
outside of the pericardial cells.”
In Fig. 384, where the nests of leucocytes (_l_) are shown, it is
evident that they are formed where observed, and “could not have
come from the pericardial cells, which have their own structure and
their special function,” these cells being very large and
characteristic.
In Kowalevsky’s preparations of Truxalis, the pericardial cells with
deposits of carmine and the groups of leucocytes (Fig. 385, _l_ and
_l′_) stained with India ink, we have to deal with elements
absolutely different. If the formation of leucocytes was caused by
the pericardial cells, these last would be obliged to free
themselves from their contents and to modify their essential nature.
_c._ The œnocytes
[Illustration:
FIG. 386.—Cluster of œnocytes from a nearly mature Phryganeid larva:
_o_, œnocytes; _t_, large tracheal branch; _tt_, smaller tracheal
ramifications; _h_, tracheal hypodermis.
]
[Illustration:
FIG. 387.—A nearly mature embryo of Xiphidium ensiferum: _o_, _o_,
œnocyte clusters seen from the surface through the integument; _a_,
pleuropodium of the right side (appendage of the first abdominal
segment); _s_, styli; _c_, cercopods.—This and Fig. 386 after
Wheeler.
]
These cells (Fig. 386), with the exception of the eggs, are the largest
in the body, and occur in most if not all winged insects. They were
called _œnocytes_ (_oinos_, wine; _kustis_, cyst), by Wielowiejski in
allusion to their wine-yellow color. These cells are arranged
segmentally (Fig. 387) in clusters, held in place by tracheæ, and are
situated mostly on each side of the abdomen, rarely being found in the
adjoining parts of the thorax. They are more or less intimately
associated with the blood and fat-body. Unlike the fat-body, however,
they arise in embryonic life from the ectoderm, either by delamination
or by immigration, just behind the tracheal involutions.
The separate cells of each cluster are usually separate, but in rare
cases may fuse in pairs or form smaller clusters. In shape they are
round or oval, often sending out pseudopodia-like processes, by
which they are attached to the tracheal twigs or to each other. “The
cytoplasm, which is very abundant, is full of yellowish granules and
is sometimes radially situated towards its periphery. The large
spherical or oval nucleus contains a densely wound and delicate
chromatic filament.” (Wheeler.)
Graber first pointed out the identity of these clusters of cells
with certain metameric cell-masses in insect embryos, observed by
Tichomiroff in those of the silkworm, and by Korotneff in the embryo
mole-cricket.
Although they resemble the blood corpuscles in some insects, they
are always much larger, and do not seem to be amœboid, while they
are never seen to undergo self-division, or to exhibit any
appearance of giving rise to the blood-cells (Wheeler). They have
not yet been detected in Thysanura (Synaptera) or in Myriopoda.
_d._ The phosphorescent organs
Phosphorescence is not infrequent in the Protozoa, cœlenterates, worms,
and has been observed in the bivalve Pholas, in a few abyssal Crustacea,
in myriopods (Geophilus), in an ascidian, Pyrosoma, and in certain
deep-sea fishes.
[Illustration:
FIG. 388.—_A_, sagittal section through the hinder end of a male
Luciola, the organs above the phosphorescent plate only drawn in
outline: _s_, integument of the last segment, somewhat removed by
the section-knife from the phosphorescent tissues; _d_, dorsal layer
of the phosphorescent plate penetrated by irregular tracheal
branches, and rendered opaque by numerous urate concretions imbedded
in it; _v_, ventral phosphorescent layer of the plate, with
perpendicular tracheal stems whose branches, where they pass into
capillaries, bear lumps which stain brown with osmic acid; _n_,
structureless substance (coagulum?) filling the end of the last
ventral segment. _B_, isolated portion of the ventral layer of the
phosphorescent plate; _tr_, tracheal stem surrounded by a
cylindrical lobe: _p_, parenchym cell attached to the cylinder; _c_,
capillary, without the spiral threads; _m_, coagulum stained brown.
_C_, a tracheal stem of the ventral layer: at the fork of the
brown-stained capillaries are lumps stained brown with osmic acid.
_D_, a part of _C_, more highly magnified, showing the remains of
the tracheal end-cells (_tc_) enveloping the brown lumps
(_m_).—After Emery.
]
In insects luminosity is mostly confined to a few Coleoptera, and
besides the well-known fireflies, an Indian Buprestid (_Buprestis
ocelata_) is said to be phosphorescent; also a telephorid larva. Other
luminous insects are the Poduran Anurophorus, Fulgora, certain Diptera
(_Culex_, _Chironomus_[60] and _Tyreophora_), and an ant (Orya).
The seat of the light is the intensely luminous areas situated either in
the head (Fulgora), in the abdomen (Lampyridæ), or in the thorax (in a
few Elateridæ of the genus Pyrophorus). The luminous or photogenic organ
is regarded by Wielowiejski and also by Emery as morphologically a
specialized portion of the fat-body, being a plate consisting of
polygonal cells, situated directly under the integument, and supplied
with nerves and fine tracheal branches.
In Luciola as well as in other fireflies, including Pyrophorus, the
phosphorescent organ or plate consists, as first stated by Kölliker, of
two layers lying one over the other, a dorsal one (Fig. 388, _d_) which
is opaque, chalky white, and non-photogenic, and a lower one (_v_), the
active photogenic layer, which is transparent. Through the upper or
opaque layer and on its dorsal surface extend large tracheæ and their
horizontal branches, from which arise numerous very fine branches which
pass down perpendicularly into the transparent or photogenic layer of
the organ. Each tracheal stem, together with its short branches, is
enveloped by a cylindrical mass of transparent tissue, so that only the
short terminal branches or very fine tracheal capillaries project on the
upper part of the cylinder. These finest tracheal capillaries are not in
Luciola filled with air, but with a colorless fluid, as was also found
by Wielowiejski and others in Lampyris.
These transparent cylinders, with the tracheæ within, forming
longitudinal axes, resemble lobules. These lobules are so distributed
that they appear on a surface section of this plate as numerous round
areas in which circular periphery the tracheal capillaries are arranged
with the axially disposed tracheal end-cells. These “tracheal end-cells”
are only membranous enlargements at the base of the tracheal capillaries
(Wielowiejski). The cylindrical lobules are separated from each other by
a substance consisting of abundant large granular cells (parenchym
cells) among which project the tracheal capillaries. The cylindrical
lobules extend to the hypodermis and come in contact only by their
lateral faces with the parenchym.
The structure of the upper opaque chalky white layer of the
phosphorescent organ is, compared with that of the photogenic lower
portion, very simple. In its loose, pappose, mass are no cellular
elements, but when treated with different reagents it is seen to be
filled with countless urate granules (guanine) swimming in the fluid it
contains, the cell plasma appearing to be dissolved, the cells having
lost their cohesion.
In comparing the phosphorescent plate or organ of Luciola with that of
Lampyris, the general structure, including the clear cell elements of
the cylindrical lobules, which envelop the perpendicular tracheal twigs
and their branches, and also the granular parenchymatous cells are alike
in both, though the arrangement and distribution of the elements in
Luciola is more regular, in Lampyris the tracheal stems being
irregularly scattered through the parenchym.
Wielowiejski found in the larval and female Lampyris a higher degree of
differentiation than in the male, and Luciola has a more differentiated
photogenic organ than Lampyris, as seen in the more regular structure of
the lobules.
As regards the light-apparatus of Pyrophorus, or the cucujo, Heinemann
shows that, as in the Lampyridæ, it consists of distinct cells, and may
be regarded as a glandular structure. It is rich in tracheæ and the
other parts already described. In still later researches on a Brazilian
Pyrophorus Wielowiejski shows that the phosphorescent plate consists of
two layers, the upper usually being filled with crystalline urate
concretions, and entirely like those of the Lampyridæ, consisting of
distinct polygonal cells, among which are numerous tracheal stems, with
tænidia, coursing in different directions, when freshly filled with air,
and sending capillaries into the underlying photogenic layer. The latter
shows in its structure a striking difference in the cellular arrangement
from that of Lampyrids. In the upper or non-photogenic layer are
tracheal capillaries which pass down into the underlying cellular plate
and which are in the closest possible relations with the single cells—a
point overlooked by Heinemann.
=Physiology of the phosphorescence.=—As is well known, the
phosphorescence of animals is a scintillating or glowing light emitted
by various forms, the greenish light or luminous appearance thus
produced being photogenic, _i.e._ without sensible heat.
Langley rates the light of the firefly at an efficiency of 100 per cent,
all its radiations lying within the limits of the visible spectrum.
“Langley has shown that while only 2.4 per cent of luminous waves are
contained in the radiation of a gas-flame, only 10 per cent in that of
the electric arc, and only 35 per cent in that of the sun, the radiation
of the firefly (_Pyrophorus noctilucus_) consists wholly of visible
wave-frequencies.” (Barker’s Physics, p. 385.)
The spectrum of the light of the cucujo was found by Pasteur to be
continuous. (C. R. French Acad. Sc. 1864, ii, p. 509.) A later
examination by Aubert and Dubois showed that the spectrum of the light
examined by the spectroscope is very beautiful, but destitute of dark
bands. When, however, the intensity diminishes, the red and orange
disappear, and the green and yellow only remain.
Heinemann studied the cucujo at Vera Cruz, Mexico. At night in a dark
room it radiates a pale green light which shows a blue tone to the
exclusion of any other light. The more gas or lamp light there is
present, the more apparent becomes the yellowish green hue, which in
clear daylight changes to an almost pure very light yellow with a very
slight mixture of green. “In the morning and evening twilight, more
constantly and clearly in the former, the cucujo light, at least to my
eyes, is an intensely brilliant yellow with a slight mixture of red. In
a dark room lighted with a sodium light the yellow tone entirely
disappears; on the other hand, the blue strikingly increases.” As
regards the spectrum he found that almost exactly half of the blue end
is wanting and that the red part is also a little narrower than in the
spectrum of the petroleum flame.