THE COCKROACH OF THE PAST.
By S. H. SCUDDER, of the U.S. Geological Survey.
_SPECIAL REFERENCES._
BERENDT, G. C. Mémoire pour servir à l’histoire des Blattes
antédiluviennes (Ann. Soc. Entom., France, V.). Paris, 1836. 8vo.
BRODIE, P. B. A History of the Fossil Insects in the Secondary
Rocks of England. London, 1845. 8vo.
GEINITZ, F. E. Die Blattinen aus der unteren Dyas von Weissig (Nova
Acta. Acad. Leop.-Carol., XLI.). Halle, 1880. 4to.
GERMAR, E. F., und BERENDT, G. C. Die im Bernstein befindlichen
Hemipteren und Orthopteren der Vorwelt. Berlin, 1856. Fol.
GOLDENBERG, F. Zur Kenntniss der Fossilen Insekten in der
Steinkohlenformation (Neues Jahrb. Miner). Stuttgart, 1869. 8vo.
---- Fauna Saræpontana Fossilis. Heft 1–2, Saarbrücken, 1873, 1877.
4to.
HEER, O. Ueber die fossilen Kakerlaken (Viertelj. Naturf. Ges.,
Zürich, IX.). Zürich, 1864. 8vo.
KLIVER, M. Ueber einige Blattarien ... aus der Saarbrücker
Steinkohlenformation (Palæontogr. XXIX.). Cassel, 1883. 4to.
KUSTA, J. Ueber enige neue Böhmische Blattinen (Sitzungsb. böhm.
Ges. Wissensch, 1883). Prag. 8vo.
SCUDDER, S. H. Palæozoic Cockroaches (Mem. Bost. Soc. Nat. Hist.,
III.). Boston, 1879. 4to.
---- The Species of Mylacris (_Ibid_). Boston, 1884. 4to.
---- A Review of Mesozoic Cockroaches (_Ibid_). Boston, 1886. 4to.
---- Triassic Insects from the Rocky Mountains (Amer. Journ. Sc.
Arts[3], XXVIII.). New Haven, 1884. 8vo.
---- Systematische Uebersicht der fossilen Myriopoden, Arachnoideen
und Insekten (Zittel, Handb. Palæont. I. Abth., Bd. II.). München,
1885. 8vo.
WESTWOOD, J. O. Contributions to Fossil Entomology (Quart. Journ.
Geol. Soc., Lond., X.). London, 1854. 8vo.
Like all useful scavengers, the Cockroach is looked upon nowadays as
an unmitigated pest. It has, however, a certain right to our regard,
for it comes of a venerable antiquity. Indeed, palæontologically
considered, no Insect is so interesting as the Cockroach. Of no other
type of Insects can it be said that it occurs at every horizon where
Insects have been found in any numbers; in no group whatever can the
changes wrought by time be so carefully and completely studied as
here; none other has furnished more important evidence concerning
the phylogeny of Insects. Even the oldest known air-breathing animal
has been claimed (though I think erroneously) as a Cockroach; yet,
however that may be, it is certain that in the most ancient deposits
which have yielded any abundance of Insect remains, the Coal Measures,
they so far outnumber all other types of Insects, that this period,
as far as its hexapodal fauna is concerned, may fairly be called
the _Age of Cockroaches_. And though the subsequent periods show an
ever-diminishing percentage of this family when compared with the
total synchronous Insect fauna, yet the existing species are counted
by hundreds, and the fecundity of some, attested by every housewife,
may be looked upon as a sufficient explanation of the persistence of
this antique type. The Cockroach is, therefore, a very aristocrat among
Insects.
Our knowledge of its past is derived almost entirely from its wings;
perhaps because these organs are the farthest removed from the
nourishing fluids of the body, which on death become one of the agents,
or at least the media, of putrefaction and consequent obliteration. At
all events, whatever the cause, these chitinous membranes, with their
network of supporting rods, and even not infrequently with the minutest
reticulation of the membrane itself, are preserved with extraordinary
fidelity, and in such abundance that, by comparison with similar parts
in existing forms, we may reach some general conclusions concerning the
life of the past of no little interest.
The first thing that would strike an observer, looking at the ancient
Cockroaches, would be their _general_ resemblance to the living.
Excepting for their usually larger size,[194] were we to have the
oldest known Cockroaches in our kitchens to-day, the householder would
take no special note of them--unless, indeed, the transparency of their
wings (shortly to be mentioned) were to give them a somewhat peculiar
aspect. There would be the same rounded pronotal shield, the same
overlapping wings, coursed by branching veins, the same smooth curves
and oval flattened form of the whole creature, and doubtless also
the same scurrying movements. Indeed, some accurate observers--so, I
suppose, we must call them--have failed to take note of some important
and very general distinctions between the living and the dead. Thus
Gerstaecker, in a work begun twenty years ago, and not yet finished,
said, near its beginning,[195] “Not a single species of Insect has
yet been found in the Carboniferous rocks which does not fall, on
closer examination (_mit voller Evidenz_), not only in an existing
order, but even almost completely in the same family as some living
form, and only presents striking distinctions when compared with the
species themselves.” He further specifies the Cockroaches described
from the Coal Measures, by Germar and Goldenberg, as agreeing in every
distinguishing family characteristic with those of the present day.
[194] Yet none were so large as our largest living forms; their
average size was very nearly that of _Periplaneta americana_.
[195] Die Klassen und Ordnungen der Arthropoden. Leipzig, 8vo, p. 292.
In one sense, indeed, this is true. We separate the living Cockroaches
from other kinds of Orthoptera as a “family” group, and “Cockroaches”
have existed since the Coal Measures at least; yet the structure of
every one of the older types is really so peculiar that none of them
can be brought within the limits of the family as it now exists. We
recognise ours, indeed, as the direct descendants of the ancient forms,
but so changed in structure as to form a distinct group. A parallel
case is found in the Walking-sticks, and is even more obvious. The
recent researches of M. Charles Brongniart have brought to view a
whole series of forms in Carboniferous times, which are manifestly
the progenitors of living Walking-sticks, with their remarkably long
and slender stick-like body, attenuated legs, and peculiar appendages
at the tip of the abdomen. Existing forms are either wingless or else
have opaque elytron-like front wings, and very ample, gauzy, fan-like
hind wings; while the Carboniferous species are furnished with four
membranous wings, almost precisely alike, and so utterly different from
those of existing types that, before the discovery of the bodies, these
wings were universally classed as the wings of Neuropterous Insects
(sensu Linneano). Thus Gerstaecker, in the very place already quoted,
says of these same wings, known under the generic name _Dictyoneura_,
that they show at least a very close relationship to the _Ephemeridæ_
of to-day.
One principal difference here alluded to--the exact resemblance,
except in minor details, of the front and hind wings, and, as
consequent therewith, _equal diaphaneity in both_--is found indeed
in all palæozoic insects, with exceedingly few exceptions;[196] it
is one of their most characteristic and pervading peculiarities.
It marks one phase of the movement in all life from homogeneity to
heterogeneity--from the uniform to the diverse. In the Cockroaches of
to-day a few are found in which the tegmina are nearly as diaphanous
as the hind wings; but in the great mass the texture of the tegmina,
as in Orthoptera generally (excepting most Gryllides), is decidedly
coriaceous; and in some, _e.g._, _Phoraspis_, the veins are nearly
obliterated in the thickness and opacity of the membrane, so as to
resemble many Coleopterous elytra.
[196] A few elytra of Coleoptera are recently announced from the
Silesian “culm.”
Three principal differences have been noticed between the ancient and
modern forms of Cockroaches. Doubtless others could be found were we
able to compare the structure of all parts of the body; and perhaps
future research and more happy discovery may yet bring them to light;
at present, however, we are compelled to restrict our comparisons to
the wings alone.
First, we have to remark the similarity of the front and hind wings in
the ancient types: a similarity which extends to their general form
(the extended anal area of the hind wings in modern types being as yet
only slightly differentiated); their nearly equal size (a corollary, to
a certain extent, of the last); the general course of their neuration
(true, in a limited sense only, of modern types); and the complete
transparency of the front as well as of the hind wing.
Second, the same number of principal veins is developed in the front
and hind wings of ancient Cockroaches; while in the front wings of
modern types two or more of the veins are blended, so as to reduce the
number of the principal stems below the normal, the hind wing at the
same time retaining its original simplicity. These principal veins
are six, counting the marginal vein, which here merely thickens the
anterior border, as one; to use the terminology of Heer, and starting
from the anterior margin, they are the _marginal_, _mediastinal_,
_scapular_, _externomedian_, _internomedian_, and _anal_. The general
disposition of these veins is as follows:--The mediastinal and scapular
veins, with their branches, which are superior (_i.e._, part from the
main vein on the upper or anterior side), terminate upon the anterior
margin. The internomedian and anal take the opposite course, and their
branches are inferior, or, at least, directed toward the inner margin;
while the externomedian, interposed between these two sets, terminates
at the tip of the wing, and branches indifferently on either side.
[Illustration: Fig. 119.--Schematic view of Wing of Palæozoic
Cockroach, showing the veins and areas.]
Now these veins are all present in both front and hind wings of
palæozoic Cockroaches, and also in the hind wings of existing species;
but in the front wings or tegmina of the latter the number is never
complete, the externomedian vein being always amalgamated either with
the scapular, or with the internomedian, and the mediastinal frequently
blended with the scapular vein.
The hind wings are thus shown to be conservative elements of structure,
since they have preserved from the highest antiquity both their
transparency and their normal number of veins. They have retained the
use to which they were first put, and the changes that have come about,
such as the wider expansion of the anal area, have been in fuller
development of the same purpose; while the front wings, in virtue of
their position in repose, have become more and more protectors of the
hind wings, and have gradually lost, in part, if not entirely, their
original use. The hind wings of existing Insects, thus protected,
have given less play to selective action, and have become to some
degree interpreters for us of the more complicated structure, the more
modernised anatomy, the more varied organisation of the front wing.
A third distinction between palæozoic and modern Cockroaches is found
in the veinlets of the anal area. These, unlike the branches of the
other veins, do not part from the main anal vein at various points
along its course, but form a series of semi-independent veinlets, and
in palæozoic Cockroaches take the same general course as the main anal
vein, or “anal furrow” (the curved, deeply sunken vein that marks
off the anal area from the rest of the front wing, both in ancient
and modern Cockroaches), and terminate at sub-equidistant intervals
upon the inner margin; while in modern Cockroaches these veins either
run sub-parallel to the inner margin and terminate on the descending
portion of the anal furrow, or they form a fusiform bundle and
terminate in proximity to one another and to the tip of the anal furrow.
These differences, which were mentioned by Germar and Goldenberg,
and their universality pointed out in my memoir on Palæozoic
Cockroaches,[197] seem to warrant our separating the older forms from
the modern as a family group, under the name of _Palæoblattariæ_; this
family has been thus characterised:--
[197] Memoirs Bost. Soc. Nat. Hist., III., 23 seq. (1880).
Fore wings diaphanous, generally reticulated, and nearly symmetrical on
either side of a median line. Externomedian vein completely developed,
forking in the outer half of the wing, its branches generally occupying
the apical margin; internomedian area broad at base (beyond the anal
area), rapidly tapering apically, and filled with oblique mostly
parallel veins, having nearly the same direction as the anal veinlets,
which, like them, strike the inner margin.
About eighty palæozoic species have been published up to the present
time, and have been grouped in two sub-families and thirteen genera.
Besides these, Brongniart has not yet given any hint of how many have
been found at Commentry, a French locality which may be expected to
increase the number largely, and about twenty undescribed species are
known to me from the American Carboniferous rocks.
[Illustration: Fig. 120.--_Etoblattina mazona_ Scudd. × 3. (The outline
of natural size.) Carboniferous, Illinois.]
The two tribes or sub-families differ in the structure of the
mediastinal vein; in one type (_Blattinariæ_) the branches part from
the main stem as in the other veins, at varying distances along its
course (see the figure of _Etoblattina_); in the other (_Mylacridæ_)
they spread like unequal rays of a fan from the very base of the wing
(see the figure of _Mylacris_). What is curious is that the latter
type has been found only in the New World, while the former is common
to Europe and America. The latter appears to be the more archaic type,
since it is probable that the primeval Insect wing was broad at the
base, as is the general rule in palæozoic wings, and had the veins
somewhat symmetrically disposed on either side of a middle line; in
this case the mediastinal and anal areas would be somewhat similar and
more or less triangular in form, and the space they occupied would be
most readily filled by radiating veins; such a condition of things,
which we find in the _Mylacridæ_, would naturally precede one in which
the mediastinal vein, to strengthen the part of the wing most liable
to strain, should, as in the _Blattinariæ_, follow the basal curve of
the costal margin, and throw its branches off at intervals toward the
border, much after the fashion of the mediastinal vein.
[Illustration: Fig. 121.--_Mylacris anthracophilum_ Scudd. × 2.
Carboniferous, Illinois.]
This view of the relative antiquity of the two tribes of
_Palæoblattariæ_ is supported by the fact that while in both of them
the internomedian branches show a tendency to repeat the general course
of the anal nervules, as in the corresponding veins of the costal
region, this tendency is lost in modern types; and among those ancient
_Blattinariæ_, which are esteemed highest in the series, there is a
marked tendency toward a loss of this repetition of the style of
branching of the mediastinal and anal offshoots by the scapular and
internomedian respectively.
A certain amount of geological evidence may also be claimed in support
of this view. A survey of the species of the two groups found up to
the present time in America, published and unpublished, shows that all
the _Mylacridæ_ are found below the Upper Carboniferous, while more
than half the _Blattinariæ_ are found in or above it. This results
largely from a recent and as yet unpublished discovery of _Blattinariæ_
in the Upper Coal Measures of Ohio and West Virginia, which in their
general features are much nearer than previously discovered American
Cockroaches to the European _Blattinariæ_, the latter of which come
generally from Upper Carboniferous beds. The _Mylacridæ_ have therefore
been found in America in strata generally regarded as older than those
which in Europe have yielded Cockroaches, and this gives a sufficient
explanation why no _Mylacridæ_ have yet been found in the Old World.
In America one is mostly dealing with absolutely older forms, and they
naturally give that continent a more old-fashioned look, when we regard
the Carboniferous fauna as a whole. As already stated, a wing from the
French Silurian (_Palæoblattina Douvillei_ Brongn.) has been claimed as
a Cockroach, but without good reason, and to see a real old Cockroach
one must look to America.
Up to this point we have contrasted the palæozoic Cockroaches with the
existing forms only, and finding such important distinctions between
them, we naturally turn with some curiosity to the intermediate
mesozoic and tertiary formations.
Now, not only are the mesozoic species as numerous (actually, but not
relatively) as the palæozoic, but a recent discovery of a Triassic
fauna of considerable extent, in the elevated parks of Colorado,
presents us with a series of intermediate forms between those peculiar
to the Coal Measures and those characteristic of the later mesozoic
rocks. Excluding, however, for a moment this Triassic fauna, we may
say of the later mesozoic species that they are _Neoblattariæ_, not
_Palæoblattariæ_, though they still show some lingering characteristics
of their ancestry. Thus the front wings are in general of a less
dense texture than in modern times, but without the perfect
diaphaneity of the palæozoic species; in some the anal veins fall in
true palæoblattarian fashion on the inner margin, while in others
which cannot be dissociated generically from them, the anal veins
are disposed as in modern types. But in all there is a loss of one
of the principal veins, or rather an amalgamation of two or more--a
characteristic of more fundamental character. As a general rule,
moreover, to which we shall again advert, the mass of the species are
of small size, in very striking contrast to the older types.
[Illustration: Fig. 122.--_Neorthroblattina Lakesii_ Scudd. × 5. Trias,
Colorado.]
To return now to the Triassic deposits of Colorado, we recognize here
an assemblage of forms of a strictly intermediate character. Here
are _Palæoblattariæ_ and _Neoblattariæ_, side by side. The larger
proportion are _Palæoblattariæ_, but all of them are specifically,
and most of them generically, distinct from palæozoic species, and
all rank high among _Blattinariæ_; still further, the species are
all of moderate size, their general average being but little above
that of mesozoic Cockroaches, and only a little more than half that
of palæozoic types. The _Neoblattariæ_ of this Triassic deposit are
still smaller, being actually smaller than the average mesozoic
Cockroach, and one or two of them, of the genus _Neorthroblattina_
(see figure of _N. Lakesii_), have marked affinity to one of the
genera of Palæoblattariæ (_Poroblattina_) peculiar to the same beds,
differing mainly in the union or separation of the mediastinal
and scapular veins; while others, as _Scutinoblattina_, have a
_Phoraspis_-like aspect and density of membrane. This novel assemblage
of species bridges over the distinctions between the _Palæoblattariæ_
and _Neoblattariæ_. We find, first, forms in which the front wings
are diaphanous, with distinct mediastinal and scapular veins, and
the anal veinlets run to the border of the wing (_Spiloblattina_,
_Poroblattina_); next, those having a little opacity of the front
wings, with blended mediastinal and scapular, and the anal veins as
before (some species of _Neorthroblattina_); then those with still
greater opacity, with the same structural features (other species
of _Neorthroblattina_); next, those having a coriaceous or leathery
structure, blended mediastinal and scapular, and anal veins falling on
the inner margin (some species of _Scutinoblattina_); and, finally,
similarly thickened wings with blended mediastinal and scapular,
and anal veins impinging on the anal furrow (other species of
_Scutinoblattina_).
It is not alone, however, by the union of the mediastinal and scapular
stems that the reduction of the veins in the wings of later Cockroaches
has come about; for in many mesozoic types the externomedian vein is
blended with one of its neighbours, while in others not only are the
mediastinal and scapular united, but at the same time the externomedian
and internomedian.
As regards the other structural distinction between the _Palæoblattariæ
and Neoblattariæ_--the course of the anal nervules--there is much
diversity, and very imperfect knowledge, since this very portion of
the wing is not infrequently lost, a fracture most readily occurring
at the anal furrow. In most of the mesozoic genera, the anal nervules,
as far as known, strike the margin; but the larger portion of these
show a decided tendency to trend toward the tip of the anal furrow,
as in many modern forms. This feature can hardly be considered
as firmly established in mesozoic times, and the same genus, as
_Scutinoblattina_, may contain species which differ in this respect.
A further peculiarity of mesozoic Cockroaches, already alluded to, is
their generally small size. The average length of the front wing of
palæozoic Cockroaches has been estimated to be 26 mm., that of the
Triassic _Palæoblattariæ_ is about 16 mm., while that of the mesozoic
_Neoblattariæ_ is 12·5 mm. One exception to this small size must be
noted in the species from the Jura of Solenhofen, all of which were
large and some gigantic, one wing reaching the length of 60 mm., or
about the size of our largest tropical _Blaberæ_. If we omit these
exceptional forms, the average length of the wing of the mesozoic
Cockroach would be scarcely more than 11 mm. Now an average of the
243 species of which the measurements are given in Brunner’s Système
des Blattaires (1865), gives the length of the front wing of living
Cockroaches as a little over 18 mm.; so that the mesozoic Cockroaches
were as a rule considerably smaller, the palæozoic Cockroaches much
larger, than the living.
[Illustration: Fig. 123.--_Mesoblattina Brodiei_ Scudd. × 4. Purbecks,
England.]
Nearly eighty species of mesozoic _Neoblattariæ_ are known, and they
are divided into thirteen genera,[198] one of which, _Mesoblattina_
(see figure of _M. Brodiei_), contains upwards of twenty species,
mainly from the Lias and Oolites of England. The Upper Oolite has
proved the most prolific, considerably more than half the species
having been found in the English Purbecks, while nearly a fourth occur
in the Lias of England, Switzerland, and Germany. Many of the English
species have been figured in Brodie’s Fossil Insects of the Secondary
Rocks of England, in Westwood’s paper on Fossil Insects in the tenth
volume of the Quarterly Journal of the Geological Society, and in
the memoir alluded to above. No species has yet been found in rocks
of different geological horizons, and the genera of the Trias are
peculiar to it. So, too, are some of the genera of the Oolite, but all
of the Liassic genera occur also in the Oolite.
[198] See a paper on mesozoic Cockroaches now printing in the Memoirs
Bost. Soc. Nat. Hist., Vol. III., p. 439 seq.
Among these mesozoic Cockroaches are some of very peculiar aspect; one,
_Blattidium_ (see figure of _B. Simyrus_), found only in the lower
Purbecks, has ribbon-shaped wings with parallel sides, longitudinal
neuration, and anal nervures with a course at right angles to their
usual direction; another, _Pterinoblattina_ (see figure of _P.
intermixta_), geologically widespread, is very broad, more or less
triangular, and has an exceedingly fine and delicate neuration, so
arranged as to resemble the barbs of a feather.
[Illustration: Fig. 124.--_Blattidium Simyrus_ Westw. × 3. Lower
Purbecks, England.]
A comparison of the neuration of the tegmina of mesozoic and recent
Cockroaches, to determine as far as possible the immediate relations
of the former to existing types, gives as yet little satisfaction.
The prolific genera, _Mesoblattina_ and _Rithma_, may be said to bear
considerable resemblance to the _Phyllodromidæ_, and the peculiar
neuration of _Elisama_ is in part repeated in the _Panchloridæ_, as
well as in some _Phyllodromidæ_ and _Epilampridæ_. _Scutinoblattina_
also reminds one in certain features of some _Epilampridæ_, like
_Phoraspis_. The other genera appear to have no special relations to
any existing type. As a whole, it would appear as if the _Blattariæ
spinosæ_ approached closer to the mesozoic forms than do the _Blattariæ
muticæ_.
[Illustration: Fig. 125.--_Pterinoblattina intermixta_ Scudd. × 4.
Upper Lias, England.]
As to the tertiary Cockroaches we know very little, exceedingly few
having been preserved, even in amber--that wonderful treasury of fossil
Insects. Here first we come across apterous forms, _Polyzosteria_
having been recognised in Prussian amber,[199] together with winged
species, which seem to be _Phyllodromidæ_; these are the only
_Blattariæ spinosæ_ known from the Tertiaries. Of the other group,
we have _Zetobora_, one of the _Panchloridæ_, and _Paralatindia_,
one of the _Corydidæ_, from American rocks, and _Heterogamia_ and
_Homœogamia_, one from Parschlug in Steiermark, the other from
Florissant in Colorado, belonging to the sub-family _Heterogamidæ_.
Others are mentioned, generally under the wide generic term _Blatta_,
from Oeningen, Eisleben, Rott, and even from Spitzbergen and Greenland;
but little more than their names are known to us. _Paralatindia_, from
the Green River beds of Wyoming, U.S., is the only tertiary Cockroach
yet referred to an extinct genus; but close attention has not yet been
paid even to the few tertiary Cockroaches which we know. There is no
reason to suppose that they will be found to differ more from the
existing types than is generally the case with other Insects. The more
we learn of cænozoic Insects, the more truly do we find that the early
Tertiary period was in truth the dawn of the present, the distinction
between the faunas of these remotely separated times (though not to
be compared in character) being scarcely greater than is found to-day
between the Insects of the temperate and torrid zones.
[199] The wingless creature from the Carboniferous deposits of
Saarbrücken, described by Goldenberg as a Cockroach, under the name
of _Polyzosterites granosus_, appears to be a Crustacean.
We began this review with the statement that no Insect was so important
palæontologically as the Cockroach. This would more clearly appear had
we space to pass in review the geological history of all the Insect
tribes; for then it could be shown that it was only in the passage from
palæozoic to mesozoic times that the great ordinal groups of Insects
were differentiated, and that the Triassic period therefore becomes the
expectant ground of the student of fossil Insects. Up to the present
time we do not know half a dozen Insects besides Cockroaches from
these rocks. Yet, notwithstanding this advantage on the part of the
Cockroaches, how meagre is the history, how striking the “imperfection
of the geological record” concerning them, the following tabulation of
the fossil species by their genera will show.
It here appears that there are about 80 species known from the
palæozoic rocks, two or three more than that from the mesozoic, and
only nine from the cænozoic! When we call to mind that half the
palæozoic Insects were Cockroaches, and that seven or eight hundred
species exist to-day, what shall we say of the paltry dozen[200] from
the rich tertiaries? Shall we claim that these figures represent
their true numerical proportion to their numbers in the more distant
past? Then, indeed, must the palæozoic period have been the Age of
Cockroaches; for all research into the past shows that a type once
losing ground continues to lose it, and does not again regain its
strength. The Cockroaches of to-day are no longer, as once, a dominant
group; they are but a fragment of the world’s Insect-hosts; yet even
now the species are numbered by hundreds. If this be a waning type,
what must its numbers have been in the far-off time, when the warm
moisture which they still love was the prevailing climatic feature of
the world; and how few of that vast horde have been preserved to us!
The housekeeper will thank God and take courage.
[200] This includes all possible forms; our table shows but nine.
GEOLOGICAL DISTRIBUTION OF FOSSIL COCKROACHES.
Figures in _italics_ represent the number of American species; in
roman, of European.
+---------------------+-------------------+----+----+----+----+----+----+
| |Carboniferous.| | | | U | O | M | |
| | L | M | U | P | T | L | p | l | i | T |
| | o | i | p | e | r | i | p | i | o | O |
| | w | d | p | r | i | a | e | g | c | T |
| | e | d | e | m | a | s. | r | o | e | A |
| | r. | l | r. | i | s. | | J | c | n | L |
| | | e. | | a | | | u | e | e. | S. |
| | | | | n. | | | r | n | | |
| | | | | | | | a. | e. | | |
+---------------------+----+----+----+----+----+----+----+----+----+----+
|PALÆOBLATTARIÆ. | | | | | | | | | | |
| _Mylacridæ_-- | | | | | | | | | | |
| Mylacris |_10_| .. | .. | .. | .. | .. | .. | .. | .. | 10 |
| Promylacris | _1_| .. | .. | .. | .. | .. | .. | .. | .. | 1 |
| Paromylacris | _1_| .. | .. | .. | .. | .. | .. | .. | .. | 1 |
| Lithomylacris | _2_| _2_| .. | .. | .. | .. | .. | .. | .. | 4 |
| Necymylacris | _2_| .. | .. | .. | .. | .. | .. | .. | .. | 2 |
| _Blattinariæ_-- | | | | | | | | | | |
| Etoblattina | _1_| 1 |15+ | 3+ | | .. | .. | .. | .. |} |
| | .. | .. | _6_| _1_| _1_| .. | .. | .. | .. |}28 |
| Spiloblattina | .. | .. | .. | .. | _4_| .. | .. | .. | .. | 4 |
| Archimylacris | _3_| .. | .. | .. | .. | .. | .. | .. | .. | 3 |
| Anthracoblattina | .. | 2 | 6 | 4 | _1_| .. | .. | .. | .. | 13 |
| Gerablattina | _1_| 1 | 10 | .. | .. | .. | .. | .. | .. | 12 |
| Hermatoblattina | .. | .. | 1 | 1 | .. | .. | .. | .. | .. | 2 |
| Progonoblattina | .. | .. | 2 | .. | .. | .. | .. | .. | .. | 2 |
| Oryctoblattina | _1_| .. | 1 | 1 | .. | .. | .. | .. | .. | 3 |
| Petrablattina | _1_| .. | .. | 1 | _2_| .. | .. | .. | .. | 4 |
| Poroblattina | .. | .. | .. | .. | _2_| .. | .. | .. | .. | 2 |
| |(23)| (6)|(41)|(11)|(10)| | | | |(91)|
|NEOBLATTARIÆ. | | | | | | | | | | |
|N t | | | | | | | | | | |
|o o {Ctenoblattina | .. | .. | .. | .. | .. | 1 | 2 | .. | .. | 3 |
|t {Neorthroblattina| .. | .. | .. | .. | _4_| .. | .. | .. | .. | 4 |
| s {Rithma | .. | .. | .. | .. | .. | 2 | 10 | .. | .. | 12 |
|y u {Mesoblattina | .. | .. | .. | .. | .. | 7 | 15 | .. | .. | 22 |
|e b {Elisama | .. | .. | .. | .. | .. | 1 | 5 | .. | .. | 6 |
|t - {Pterinoblattina | .. | .. | .. | .. | .. | 3 | 6 | .. | .. | 9 |
| f {Blattidium | .. | .. | .. | .. | .. | .. | 2 | .. | .. | 2 |
|r a {Nannoblattina | .. | .. | .. | .. | .. | .. | 3 | .. | .. | 3 |
|e m {Dipluroblattina | .. | .. | .. | .. | .. | .. | 1 | .. | .. | 1 |
|f i {Diechoblattina | .. | .. | .. | .. | .. | .. | 2 | .. | .. | 2 |
|e l {Scutinoblattina | .. | .. | .. | .. | _3_| .. | .. | .. | .. | 3 |
|r i {Legnophora | .. | .. | .. | .. | 1 | .. | .. | .. | .. | 1 |
|r e {Aporoblattina | .. | .. | .. | .. | .. | 3 | 6 | .. | .. | 9 |
|e s | | | | | (8)|(17)|(52)| | |(77)|
|d . | | | | | | | | | | |
| | | | | | | | | | | |
| _Phyllodromidæ_-- | | | | | | | | | | |
| “Blatta” | .. | .. | .. | .. | .. | .. | .. | 3 | .. | 3 |
| _Periplanetidæ_-- | | | | | | | | | | |
| Polyzosteria | .. | .. | .. | .. | .. | .. | .. | 2 | .. | 2 |
| _Panchloridæ_-- | | | | | | | | | | |
| Zetobora | .. | .. | .. | .. | .. | .. | .. | _1_| .. | 1 |
| _Corydidæ_-- | | | | | | | | | | |
| Paralatindia | .. | .. | .. | .. | .. | .. | .. | _1_| .. | 1 |
| _Heterogamidæ_-- | | | | | | | | | | |
| Homœogamia | .. | .. | .. | .. | .. | .. | .. | _1_| .. | 1 |
| Heterogamia | .. | .. | .. | .. | .. | .. | .. | .. | 1 | 1 |
| | | | | | | | | (8)| (1)| (9)|
+---------------------+----+----+----+----+----+----+----+----+----+----+
| GRAND TOTALS | 23 | 6 | 41 | 11 | 18 | 17 | 52 | 8 | 1 |177 |
+---------------------+----+----+----+----+----+----+----+----+----+----+
Samuel H. Scudder.
APPENDIX.
PARASITES OF THE COCKROACH.
_Spirillum, sp._ [Vibrio]. SCHIZOMYCETES.
Rectum.
_Ref._--Bütschli, Zeits. f. wiss. Zool., Bd. XXI., p. 254 (1871).
_Hygrocrocis intestinalis_, Val. CYANOPHYCEÆ.
Filaments of a very minute Alga abound in the rectum of the
Cockroach, where this species is said by Valentin to occur. The
intestine of the Crayfish is given as another habitat. Leidy
observes that the filaments which he found in the rectum of the
Cockroach are inarticulate, and do not agree with Valentin’s
description of the species.
_Ref._--Valentin, Repert. f. Anat. u. Phys., Bd. I., p. 110 (1836);
Robin, Végét. qui croissent sur l’Homme, p. 82 (1847); Leidy,
Smithsonian Contr., Vol. V., p. 41 (1853); Bütschli, Zeits. f.
wiss. Zool., Bd. XXI., p. 254 (1871).
_Endamœba (Amœba) Blattæ_, Bütschli. RHIZOPODA.
Rectum.
_Ref._--Siebold, Naturg. wirbelloser Thiere (1839) _fide_ Stein;
Stein, Organismus d. Infusions-thiere, Bd. II., p. 345 (1867);
Bütschli, Zeits. f. wiss. Zool., Bd. XXX., p. 273, pl. xv. (1878);
Leidy, Proc. Acad. N. S. Phil., Oct. 7th, 1879, and Freshwater
Rhizopods of N. America, p. 300 (1879).
_Gregarina (Clepsidrina) Blattarum_, Sieb. GREGARINIDA.
Encysted in chylific stomach and gizzard; free in large intestine.
_Ref._--Siebold, Naturg. wirbelloser Thiere, pp. 56, 71 (1839);
Stein, Müll. Arch., 1848, p. 182, pl. ix., figs. 38, 39; Leidy,
Trans. Amer. Phil. Soc., Vol. X., p. 239 (1852); Bütschli, Zeits.
f. wiss. Zool., Bd. XXI., p. 254 (1871), and Bd. XXXV., p. 384
(1881); Schneider, Grégarines des Invertébrés, p. 92, pl. xvii.,
figs. 11, 12 (1876).
_Nyctotherus ovalis_, Leidy. INFUSORIA.
Small and large intestines.
_Ref._--Leidy, Trans. Amer. Phil. Soc., Vol. X., p. 244, pl. xi.
(1852).
_Plagiotoma (Bursaria) blattarum_, Stein. INFUSORIA.
Rectum.
_Ref._--Stein, Sitzb. d. königl. Böhm. Ges., 1860, pp. 49, 50.
_Lophomonas Blattarum_, Stein. INFUSORIA.
Rectum.
_Ref._--Stein (loc. cit.); Bütschli, Zeits. f. wiss. Zool., Bd.
XXX., p. 258, plates xiii., xv. (1878).
_L. striata_, Bütschli. INFUSORIA.
Rectum.
_Ref._--Bütschli, Zeits. f. wiss. Zool., Bd. XXX., p. 261, plates
xiii., xv. (1878).
_Gordius_, sp. NEMATELMINTHA.
Specimens in the Museum at Hamburg, from Venezuela. Obtained from
some species of Cockroach.
_Oxyuris Diesingi_, Ham. NEMATELMINTHA.
Rectum, frequent.
_Ref._--Hammerschmidt, Isis, 1838; Bütschli, Zeits. f. wiss. Zool.,
Bd. XXI., p. 252, pl. xxi. (1871).
_O. Blattæ orientalis_, Ham. NEMATELMINTHA.
Rectum (much rarer than _O. Diesingi_).
_Ref._--Hammerschmidt (_loc. cit._); Bütschli, Zeits. f. wiss.
Zool., Bd. XXI., p. 252, pl. xxii. (1871).
Other species of _Oxyuris_ are said to occur in the same situation,
_e.g._, _O. gracilis_ and _O. appendiculata_ (Leidy, Proc. Acad.
N. S. Phil., Oct. 7th, 1879), and _O. macroura_ (Radkewisch, quoted
by Van Beneden in Animal Parasites, Engl. trans., p. 248).
_Filaria rhytipleurites._ NEMATELMINTHA.
Encysted in the fat-body of the Cockroach; sexual state in the
alimentary canal of the Rat. _Spiroptera obtusa_ is similarly
shared by the Meal-worm (larva of _Tenebrio molitor_) and the Mouse.
_Ref._--Galeb, Compt. Rend., July 8th, 1878.
_Acarus_, sp. ARACHNIDA.
Found by Cornelius upon the sexual organs of a male Cockroach.
_Ref._--Cornelius, Beitr. zur nähern Kenntniss von _Periplaneta
orientalis_, p. 35, fig. 23 (1853).
_Evania appendigaster_, L. INSECTA (_Hymenoptera_).
A genus of Ichneumons, parasitic upon _Periplaneta_ and _Blatta_.
_Ref._--Westwood, Trans. Ent. Soc., Vol. III., p. 237; Ib., Ser.
II., Vol. I., p. 213.
_Symbius Blattarum_, Sund. INSECTA (_Coleoptera_).
The apterous female is parasitic upon _P. americana_ and _B.
germanica_.
_Ref._--Sundevall, Isis, 1831.
* * * * *
SENSE OF SMELL IN INSECTS.
Since the printing of the sheets which describe the organs of special
sense, we have become acquainted with two experimental researches of
recent date, instituted for the purpose of determining whether other
organs, besides the antennæ, may be specially concerned with the
perception of odours by Insects.
Prof. Graber (Biol. Centralblatt, Bd. V., 1885) has described extensive
and elaborate experiments upon various Insects, tending to the
conclusion that the palps and the cerci may be sensitive to odours,
and that in special cases the palps may be even more sensitive in this
respect than the antennæ. Cockroaches, decapitated, but kept alive for
some days, were found to perceive odours by means of their cerci. His
general conclusion is that Insects have no special sense of smell,
but that various parts of the surface of the body are furnished with
nerve-endings capable of perceiving strong odours. Prof. Graber’s
results are known to us only through the abstract given by Prof.
Plateau in the paper next to be mentioned.
Prof. Plateau (Compt. rend. de la Soc. Entom. de Belgique, 1886)
relates experiments upon the powers of scent resident in different
organs of the Cockroach. Two Cockroaches had their palps (maxillary and
labial) removed; two others had the antennæ removed. An evaporating
dish, 8 inches in diameter, was then partly filled with fine sand.
In the centre of the dish was set a circular box of card, without
bottom, 2 inches in diameter, and 1-4/5 inches high. In this box bread
moistened with beer, a bait very attractive to Cockroaches, was placed,
and renewed daily. The four Cockroaches were allowed to run about in
the dish outside the box, and to feed upon the bread at pleasure by
climbing over the enclosure. Observations were made late at night
for a month, when it was found that, except on the first night, when
the Insects ran all over the dish, none of the Cockroaches without
antennæ made their way to the food; while twenty-three times one of the
Cockroaches without palps, but with antennæ intact, was found to be
feeding; in one instance, both were so found.
Plateau observes that a special sense of smell can only be claimed for
organs which are able to detect faint and distant odours, and that
experiments made with powerful odours close to the body of the Insect
may lead to fallacious results. The perception of faint odours cannot
be effected by the palps or cerci of the Cockroach, but only by the
antennæ.
THE END.
Printed by McCORQUODALE & CO, Limited, Leeds.