6. Young 1-nucleate individual emerged from cyst, destined to grow,
proliferating its nuclei to adult form.
a = nucleus.
b = food (?) particles in Fig. 1.]
Family 8.--TETRAMITIDAE. Body pyriform, the pointed end posterior;
flagella 4 anterior.
_Tetramitus_ (Perty) (_T. calycinus_ of Kent, Fig. 2, 11, 14), is
the "calycine monad" of Dallinger and Drysdale; _Trichomonas_,
Donne, possesses a longitudinal undulating membrane, and is an
innocuous human parasite; it is possibly related to Haemoflagellates
on one hand and to _Trichonymphidae_ on the other.
Family 9.--DISTOMATIDAE. Mouth-spots two, or one, with a distinct
construction; flagella symmetrically arranged; nucleus bilobed or
geminate. _Hexamitus_ (Duj.) (Fig. 2, 5), saprophytic and parasitic;
_Trepomonas_ (Duj.), freshwater; _Megastoma_ (Grassi) (= _Lamblia_
of Blanchard), with constricted mouth-spot and blepharoplast
(kineto-nucleus) parasitic in the small intestine of Mammals,
including Man.
Family 10.--TRICHONYMPHIDAE. Flagella numerous, sometimes
accompanied by one or more undulating membranes; cytoplasm highly
differentiated; contractile vacuole absent; all parasitic in insects
(all except _Lophomonas_ in Termites--the so-called White Ants.)
_Lophomonas_(St.) (Fig. 2, 9); parasitic in the cockroach;
_Dinenympha_ (Leidy), _Pyrsonympha_ (Leidy); _Trichenympha_ (Leidy)
(Fig. 3, 1).
Family 11.--OPALINIDAE. Flagella short, numerous, ciliform.
uniformly distributed over the flat oval body; nuclei small,
numerous, uniform.
Only genus, _Opalina_ (Purkinje and Valentin) (Fig. 3, 2-6), in
bladder and cloaca of the frog (usually regarded as an aberrant
ciliate, but E.R. Lankester expressed doubts as to its position in
the 9th edition of this encyclopaedia).
Order 2.--CHRYSOMONADACEAE. Contractile vacuole simple (in fresh-water
forms) or absent; plastids yellow or brown always present; reserves
fat.
Family 1.--CHRYSOMONADIDAE. Body naked, often amoeboid in active
state, or sometimes with a cup-like theca, a gelatinous investment,
a firm cuticle, or silicified shell; reserves fat or leucosin
(starch in _Zooxanthella_); eye-spot present. _Chromulina_ (Cienk.)
often forms a golden scum on tanks; _Chrysamoeba_ (Klebs);
_Hydrurus_ (Agardh), theca of colony forming branching tubes,
simulating a yellow Conferva in mountain torrents; _Dinobryon_
(Ehrb.) (Fig. 1, 8, 15); _Stylochrysalis_ (St.); _Uroglena_ (Ehrb.);
_Syncrypta_ (Ehrb.), and _Synura_ (Ehrb.) (Fig. 1, 5) form floating
spherical colonies; _Zooxanthella_ (Brandt), symbiotic as "yellow
cells" in Radiolaria _Foraminifera_, _Millepora_, and many
Actinozoa.
Family 2.--COCCOLITHOPHORIDAE. Body invested in a spherical test
strengthened by calcareous elements, tangential circular plates,
"coccoliths," "discoliths," "cyatholiths," or radiating rods
"rhabdoliths." These are often found in Foraminiferal ooze and its
fossil condition, chalk; when coherent as in the complete test, they
are known as "coccospheres" and "rhabdospheres." _Coccolithophora_
(Lohmann), _Rhabdosphaera_ (Haeckel).
Order 3.--CRYPTOMONADACEAE. Contractile vacuole (in freshwater forms)
simple; plastids green, more rarely red, brown or absent; reserves
starch; holophytic or saprophytic. _Cryptomonas_ (Ehrb.); _Paramoeba_
(Greeff) has yellow plastids and shows two cycles, in the one
amoeboid, finally encysting to produce a brood of flagellulae; in the
other flagellate, and multiplying by longitudinal fission (it differs
from _Mastigamoeba_ in possessing no flagellum in the amoeboid state,
though it takes in food amoeba-fashion); _Chilomonas_ (Ehrb.).
Order 4.--CHLOROMONADACEAE. Contractile vacuoles 1-3, a complex of
variable arrangement; pellicle delicate; plastids discoid
chlorophyll-bodies; reserves oil; eye-spot absent even in active
state; holophytic or saprophytic, though with an anterior blind
tubular depression simulating a pharynx. _Coelomonas_ (St.),
_Vacuolaria_ (Cienk.).
Order 5.--EUGLENACEAE. Vacuole large, a reservoir for one or more
accessory vacuoles, contractile and opening to the surface by a canal
("pharynx") in which are planted one or two strong flagella; pellicle
strong often striated; nucleus large, chromatophores green, complex or
absent; reserves paramylum granules of definite shape, and oil;
nutrition variable; body stiff or "metabolic," never amoeboid. Among
the true Flagellates these are the largest, few being below 40 [mu]
and several attaining 130 [mu] in length of cell-body (excluding
flagellum). Encysted condition common; the green forms sometimes
multiply in this state and simulate unicellular Algae.
Family 1.--EUGLENIDAE. Radial (monaxial) forms; nutrition
saprophytic or holophytic, mostly one flagellate. (1) Chromatophore
large; eye-spot conspicuous. _Euglena_ (Ehrb.) (Fig. 1, 13, 17),
with flexible cuticle and metabolic movements (this is probably
Priestley's "green matter" through which he obtained oxygen gas)--a
very common genus; _Colacium_ (Ehbg.), in its resting state epizoic
on Copepoda, which it colours green; _Eutreptia_ (Perty),
biflagellate; _Ascoglena_ (St.); _Trachelomonas_ (Ehrb.), with a
hard brown cuticle; _Phacus_ (Nitszche), with a firm rigid pellicle,
often symmetrically flattened; _Cryptoglena_ (Ehbg.). (2)
Chromatophores absent. _Astasia_ (Duj.), body metabolic; _Menoidium_
(Perty), body not metabolic, somewhat inflected and crescentic;
_Sphenomonas_ (Stein), with a short accessory trailing flagellum in
front peeled; _Distigma_ (Ehbg.) (Fig. 1, 27, 28), very metabolic,
with two unequal flagella and two dark pigment spots.
Family 2.--PERANEMIDAE. Bilaterally symmetrical, often creeping,
pharynx highly developed, with a firm rod-like skeleton, sometimes
protrusible; nutrition saprophytic and holozoic. _Peranema_ (Ehbg.)
and _Urceolus_ (Mereschowsky), uni-flagellate creeping, very
metabolic. _Petalomonas_ (St.), uni-flagellate flattened with a deep
ventral groove, not metabolic; _Heteronema_ (Duj.) and
_Tropidoscyphus_ (St.), with a small accessory anterior trailing
flagellum; _Anisonema_ (Duj.) and _Entosiphon_ (St.), with the
trailing flagellum as long as the tractellum or even much longer.
Order 6.--VOLVOCACEAE. Contractile vacuole simple anterior; cell
always enclosed in a cellulose wall (sometimes gelatinous) perforated
by the two (more rarely four, five) diverging anterior flagella;
reserves starch; chlorophyll almost always present, except in
_Polytoma_, sometimes masked by a red pigment; nutrition usually
holophytic, rarely saprophytic, never holozoic. Brood-division in
active state common, radial.
Family 1.--CHLAMYDOMONADIDAE. Cell-wall firm not gelatinous, rarely
forming colonies. Fore-end of the body with two or four (seldom
five) flagella. Almost always green in consequence of the presence
of a very large single chromatophore. Generally a delicate
shell-like envelope of membranous consistence. 1 to 2 simple
contractile vacuoles at the base of the flagella. Usually one
eye-speck. Division of the protoplasm within the envelope may
produce four, eight or more new individuals. This may occur in the
swimming or in a resting stage. Also by more continuous fission
microgametes of various sizes are formed. Conjugation is frequent.
Genera.--_Chlorangium_ (Stein), lacking green chlorophyll;
_Chlorogonium_ (Ehr.) (Fig. 1, 6, 7); _Polytoma_ (Ehr.) (Fig. 2, 8);
_Chlamydomonas_ (Ehr.) (Fig. 1, 1, 2, 3); _Haematococcus_ (Agardh) (=
_Chlamydococcus_, A. Braun, Stein); _Protococcus_ (Conn, Huxley and
Martin); _Chlamydomonas_ (Cienkowski), causes red snow and "bloody
rain"; _Carteria_ (Diesing), quadri-flagellate; _Spondytomorum_
(Ehrb.), forming floating colonies; _Coccomonas_ (St.); _Phacotus_
(Perty); _Zoochlorella_ (Brandt), is the name given to undetermined
Chlamydomonads found multiplying in the resting state within and in
symbiotic relation to other Protozoa, to the freshwater sponge,
_Ephydatia_, _Hydra viridis_, and to the Turbellarian, _Convoluta
viridis_ (in which last species the active form has been recognized as
a _Carteria_).
Family 2.--VOLVOCIDAE. Cell-wall gelatinous; always associated in
colonies; cells, as in Family 1. The number of individuals united to
form a colony varies very much, as does the shape of the colony.
Reproduction by the continuous division of all or of only certain
individuals of the colony, resulting in the production of a daughter
colony (from each such individual). In some, probably in all, at
certain times copulation of the individuals of distinct sexual
colonies takes place, without or with a differentiation of the
colonies and of the copulating cells as male and female. The result
of the copulation is a resting zygospore (also called zygote or
oospermo or fertilized egg), which after a time develops itself into
one or more new colonies.
Genera.--_Gonium_ (O.F. Muller) (Fig. 1, 14); _Stephanosphaera_
(Cohn); _Pandorina_ (Bory de Vine); _Eudorina_ (Ehr.); _Volvox_
(Ehr.)(Fig. 1, 18, 20).
The sexual reproduction of the colonies of the Volvocaceae is one of
the most important phenomena presented by the Protozoa. In some
families of Flagellata full-grown individuals become amoeboid, fuse,
encyst, and then break up into flagellate spores which develop simply
to the parental form (Fig. 1, 23 to 26). In the _Chlamydomonadidae_ a
single adult individual by division produces small individuals,
so-called "microgametes." These conjugate with one another or with
similar microgametes formed by other adults (as in Chlorogonium, Fig.
1, 7); or more rarely in certain genera a microgamete conjugates with
an ordinary individual megagamete. The result in either case is a
"zygote," a cell formed by fusion of two which divides in the usual
way to produce new individuals. The microgamete in this case is the
male element and equivalent to a spermatozoon; the megagamete is the
female and equivalent to an egg-cell. The zygote is a "fertilized
egg," or oosperm. In some colony-building forms we find that only
certain cells produce by division microgametes; and, regarding the
colony as a multicellular individual, we may consider these cells as
testis-cells and their microgametes as spermatozoa.
CYSTOFLAGELLATA(RHYNCHOFLAGELLATA of E.R. Lankester) and
DINOFLAGELLATA are scarcely more than subdivisions of Flagellata; but,
following O. Butschli, we describe them separately; the three groups
being united into his MASTIGOPHORA.
_Further Remarks on the Flagellates._--Besides the work of special
Protozoologists, such as F. Cienkowski, O. Butschli, F. v. Stein, F.
Schaudinn, W. Saville Kent, &c., the Flagellates have been a favourite
study with botanists, especially algologists: we may cite N.
Pringsheim, F. Cohn, W.C. Williamson, W. Zopf, P.A. Dangeard, G.
Klebs, G. Senn, F. Schutt; the reason for this is obvious. They
present a wide range of structure, from the simple amoeboid genera to
the highly differentiated cells of Euglenaceae, and the complex
colonies of _Proterospongia_ and _Volvox_. By some they are regarded
as the parent-group of the whole of the Protozoa--a position which may
perhaps better be assigned to the Proteomyxa; but they seem
undoubtedly ancestral to Dinoflagellates and to Cystoflagellates, as
well as to Sporozoa, and presumably to Infusoria. Moreover, the only
distinction between the _Chlamydomonadidae_ and the true green Algae
or Chlorophyceae is that when the former divide in the resting
condition, or are held together by gelatinization of the older
cell-walls (_Palmella_ state), they round off and separate, while the
latter divide by a "party wall" so as to give rise either to a
cylindrical filament when the partitions are parallel and the axis of
growth constant (_Conferva_ type), or to a plate of tissue when the
directions alternate in a plane. The same holds good for the
Chrysomonadaceae and Cryptomonadaceae, so that these little groups are
included in all text-books of botany. Again among Fungi, the zoospores
of the Zoosporous Phycomycetes (Chytrydiaceae, Peronosporaceae,
Saprolegniaceae) have the characters of the _Bodonidae_. Thus in two
directions the Flagellates lead up to undoubted Plants. Probably also
the Chlamydomonads have an ancestral relation to the Conjugatae in the
widest sense, and the Chrysomonadaceae to the Diatomaceae; both groups
of obscure affinity, since even the reproductive bodies have no
special organs of locomotion. For these reasons the Volvocaceae,
Chloromonadaceae, Chrysomonadaceae and Cryptomonadaceae have been
united as Phytoflagellates; and the Euglenaceae might well be added to
these. It is easy to understand the relation of the saprophytic and
the holophytic Flagellates to true plants. The capacity to absorb
nutritive matter in solution (as contrasted with the ingestion of
solid matter) renders the encysted condition compatible with active
growth, and what in holozoic forms is a true hypnocyst, a state in
which all functions are put to sleep, is here only a rest from active
locomotion, nutrition being only limited by the supply of nutritive
matter from without, and--in the case of holophytic species--by the
illumination: this latter condition naturally limits the possible
growth in thickness in holophytes with undifferentiated tissues. The
same considerations apply indeed to the larger parasitic organisms
among Sporozoa, such as Gregarines and Myxosporidia and
Dolichosporidia, which are giants among Protozoa.
LITERATURE.--W.S. Kent, _Manual of the Infusoria_, vol. i. Protozoa
(1880-1882); O. Butschli, _Die Flagellaten_ (in Bronn's _Thierreich_,
vol. i. Protozoa, 1885); these two works contain full bibliographies
of the antecedent authors. See also J. Goroschankin (on
Chlamydomonads) in _Bull. Soc. Nat._ (Moscow, iv. v., 1890-1891); G.
Klebs, "Flagellatenstudien" in _Zeitsch. Wiss. Zool._ lv. (1892);
Doflein, _Protozoen als Krankheitserreger_ (1900); Senn,
"Flagellaten," in Engler and Prantl's _Pflanzenfamilien_, 1 Teil, Abt.
1a (1900); R. France, _Der Organismus der Craspedomonaden_ (1897);
Grassi and Sandias, "Trichonymphidae," in _Quart. J. Micr. Sci._
xxxix.-xl. (1897); Bezzenberger, "Opa inidae" in _Arch. Protist_, iii.
(1903); Marcus Hartog, "Protozoa," in _Cambridge Nat. Hist._ vol. i.
(1906). (M. Ha.)
FLAGEOLET, in music, a kind of _flute-a-bec_ with a new fingering,
invented in France at the end of the 16th century, and in vogue in
England from the end of the 17th to the beginning of the 19th century.
The instrument is described and illustrated by Mersenne,[1] who states
that the most famous maker and player in his day was Le Vacher. The
flageolet differed from the recorder in that it had four finger-holes in
front and two thumb-holes at the back instead of seven finger-holes in
front and one thumb-hole at the back. This fingering has survived in the
French flageolet still used in the provinces of France in small
orchestras and for dance music. The arrangement of the holes was as
follows: 1, left thumb-hole at the back near mouthpiece; 2 and 3,
finger-holes stopped by the left hand; 4, finger-hole stopped by right
hand; 5, thumb-hole at the back; 6, hole near the open end. According to
Dr Burney (_History of Music_) the flageolet was invented by the Sieur
Juvigny, who played it in the _Ballet comique de la Royne_, 1581. Dr
Edward Browne,[2] writing to his father from Cologne on the 20th of June
1673, relates, "We have with us here one ... and Mr Hadly upon the
flagelet, which instrument he hath so improved as to invent large ones
and outgoe in sweetnesse all the basses whatsoever upon any other
instrument." About the same time was published Thomas Greeting's
_Pleasant Companion; or New Lessons and Instructions for the Flagelet_
(London, 1675 or 1682), a rare book of which the British Museum does not
possess a copy. The instrument retained its popularity until the
beginning of the 19th century, when Bainbridge constructed double and
triple flageolets.[3] The three tubes were bored parallel through one
piece of wood communicating near the mouthpiece which was common to all
three. The lowest notes of the respective tubes were [Musical notes: D B
G]
The word flageolet was undoubtedly derived from the medieval Fr.
_flajol_, the primitive whistle-pipe. (K. S.)