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1 66 DESIGN IN NATURE<br />
PLATE LXVI {continued)<br />
Fig. 11.—Aiiinifilcuk {Podostoma Jiliyerum) with Hagelliferous pseudopodia extended. />, Nucleus ; cv, contractile vesicle, x 2.50<br />
(Clap, and Lach.).<br />
Fig. 12.—Animalcule {Pudostoma fiUcjermn) with pseudopodia retracted. Figs. 11 and 12 illustrate the remarkable power pOHsessed<br />
by animalcules of voluntarily changing shape in the absence of nervi-, muscle, or other structure. It will be observed that the<br />
extended pseudopodia seen in Fig. 12 are conical at their roots and are not produced by constriction or contraction. J liey are clue<br />
to a vital extrusion or pushing out of the living sarcode from within (centrifugal movement), iind cannot be referred to contraction<br />
in any form. The appearance presented bv the pseudopodia ^\•hen drawn in or retracted, as seen in Fig. 12, is due to a vital pui^ng<br />
together of the sarcode (centripetal moveiiient.) Elasticity plays quite an unimportant part in the pseudopodic movements. Ihe<br />
centrifugal and centripetal movements here referred to occur in muscle and in all living .substances capable of changing shape. Ihey<br />
are inherent and fundamental, and are the harbingers of the rhythmic movements by which the respiration and circulation are<br />
carried on in the higher animals.<br />
Fig. 13.—Normal animalcule (Reptomomts caudiita) ingesting food by peripheral extension of its body-sarcode. «, Nucleus;<br />
cv, contractile vesicle, x 800 (W. S. Kent). The life of the zooid is devoted almost exclusively to feeding ; a remark which applies to<br />
most of the lower animals.<br />
Fig. 14.—Dorsal view of same with short pseudopodal extensions.<br />
Fig. 15.— Profile view of same.<br />
Fig. 16.—Animalcule (Mudigamceba simplex) with frustule of diatom attached by sarcode thread, x 800 (\\. S. Kent). The<br />
sarcode, which can be extruded and withdrawn at pleasure, can be employed either for seizing or ejecting food.<br />
Fig. n.—Euchitimia Virchmrii, x 370 (Haeckel). Illustrates concentric and radiating arrangements in rudimentary animal<br />
forms similar to those found in crystals, scales of fishes, shells, bones, the transverse sections of plants and trees, and different parts of<br />
the higher plants and animals. These concentric and radiating arrangements practically represent lines of force and growth.<br />
Fig. 18.—Adult animalcule (Noctiluca), donsal view (Huxley). Shows median groove, .stylate rod, and tooth-like process.<br />
Fig. 19.— Adult animalcule (Noctiluca), ventral view. Shows oral cavity with tooth-like process, and contained cilium.<br />
Fid. 20.—Typical zooids, x 1200. These zooids are fixed, and supply themselves with food by the aid of their flagella, which,<br />
swirling about, produce currents which cause the food particles to enter the cup-shaped collar which forms the upper part of the body.<br />
Fig. 21.—Colony of two zooids {Godosicjafin-nitn) on one pedicle, x 1200 (W. S. Kent).<br />
Fig. 22.—Free swimming and attached condition of monadiforni germ {Monosiqa rjlobosa) ; the collar and pedicle being not yet<br />
developed, x 1200 (W. S. Kent).<br />
Fig. 23.—A single zooid or animalcule {Gododya allioiiirs), with its body spherically, and its collar conically contracted, x 800<br />
(W. S. Kent). Shows centripetal, and, by implication, centrifugal movements in the body and collar of the zooid. The contractile<br />
vesicles of the body (cv) execute similar movements. In the zooid three sets of centripetal and centrifugal movements occur ; the one<br />
set in the collar, a second in the body, and a third in the contractile vesicles. The voluntary and involuntary movements (fundamentally<br />
rhythmic in character) as witnessed in the higher animals are here clearly foreshadowed, n, Nucleus or endoplast.<br />
FiG. 24.—A free-floating colony-stock of five zooids (DemnarMa moniliformis) united laterally, x 1000 (W. S. Kent).<br />
Fig. 25.—Zooid sending out slender pseudopodic processes ; collar and Hagellum extended, n,, Nucleus ; cv, contractile<br />
vesicle, x 2000.<br />
F'iG. 26.—Two zooids assuming an amoeboid condition ; collars and Hagella retracted. Both are sending out pseudopodic processes,<br />
X 2000 (\V. S. Kent). Figs. 25 and 26 illustrate the power possessed by zooids of changing sha]ie centrifugally and centri-<br />
petally. This power of changing shape, as explained, is a fundamental endowment in rudimentary animals, and in the tissues<br />
(especially the muscular tissues) of the higher animals.<br />
PLATE LXVII<br />
This plate illustrates the extraordinary povs^ers possessed by zooids and monads of voluntarily changing shape<br />
by centrifugal and centripetal movements, and of reverting to simpler amoeboid conditions prior to reproducing<br />
themselves.<br />
Fk;. 1.—Social colony of zooids (Sdliniujn'ca amphoridium) adhering to confervoid filament, x 625,<br />
Fig. 2.—One of the same more highly magnified with collar expanded, x 1250. Shows nucleus and contractile vesicles.<br />
Fig. 3.—Another of same with collar contracted within lorica supported on short pedicle. Figs. 2 and 3 attbrd excellent examples<br />
of the power possessed by zooids of opening and closing their collars by centrifugal and centripetal movements.<br />
Fig. 4.—Another of same encysted within lorica, showing retrogression to amoebic primitive condition.<br />
Fig. .').—Another of same with collar retracted, tlagellum protruding and thickened at base, body sarcode projectiii" and lobose.<br />
Shows how every portion of the sarcode can cliange shape.<br />
Fig. G.— Another of .same with filamentous pseudopodia proceeding from top of lorica.<br />
Fig. 7.— Another of same where the body sarcode has assumed a branched, pinnatified appearance (J. Clark).<br />
Fig. 8. — Zooid with lorica flatti'iied below and imperfect collar (Biitschli).<br />
Fi(i. 9.— Zooid (Salpingceca marina) sending out ray-like pseudopodia ;<br />
the collar and fiagellum retracted.<br />
Figs. 10 and 11.—Sarcode ejected from body of zooid assuming stellate form. These figures afford good examples of the power<br />
possessed by sarcode of extruding its substance in wedge-shaped masses as apart from contraction and elasticity.