Picture - Cosmic Polymath

178 DESIGN IN NATURE
PLATE LXXV
PLATE LXXV
This plate reveals an obvious advance in infusorial structure and function. It displays suctorial and pre-
liensile tentacula ; some
of the latter exhibiting beautiful spiral formations and spiral movements ; it also
displays modes of division, modes of feeding and differentiation generally. In studying the lower animal
forms depicted in Plates Ixvi. to Ixxiii. inclusive it is impossible to come to the conclusion that the one is evolved
out of the other. Each in its own way is independent, and the most that can be done is to refer the individual
to a type or group having structural, functional, and developmental peculiarities. In other words, no gradual
transitions, such as evolution takes for granted, can be made out.
Figs. 1 and 2.—Extended and spirally coaitracted e.xamples of ciliated zooids (UroUptus 'iiiohilis), x 150 (Engelinaiin). Body
flexible, elongate, linear, cylindrical ; peristome very narrow ; frontal styles uncinate ; ventral and lateral setse—the latter lono- and
fine ;
nuclei or endoplasts six in number and rod-like in shape.
Figs. .3 and 4.—Dorsal and lateral views of EpicUnten radiosa, x 300 (Quennerstedt). Body elongate, anterior portion compn'ssed
and bearing at its summit five large straight radiating frontal styles ; single marginal row of setse on anterior and middle portions of
body and double row bordering caudal portion of body.
Fig. 5.—Ventral aspect of Uroleptus rattuhis, x 150. n, «, Nuclei (Stein). Body persistent in shape, linear-fusiform anterior end
rounded, tapers from central part of body and ends in long thin tail ; peristome iield narrow and extends backward one-fifth of bodv
marginal setse cover body, the ventral setie forming two rows ; endoplasts (n, n) two in number with contractile vesicle between'
Shape of body fi.sh-like.
Pig. 6.—Lateral view of Euplotes patella, x 200 (Dujardin).
Fig. 7.—Ventral view of Euplotes charon, x 300.
Fig. 8.—The same dividing by transverse fission, x 300,
Fig. 9.—The same encysted, x 300 (Stein). Figs. 7, 8, and 9 show simple forms of division and development.
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