1&2 



COLLEGE ZOOLOGY 



^ Two coiled tubes (nph), which 

 give off a number of ciliated 

 lobules (fl.c), and enter a 

 bladder (c.v), constitute the ex- 

 cretory system. The bladder con- 

 tracts at intervals, forcing the 

 contents out of the anus. Since 

 the amount of fluid expelled by 

 the bladder is very large, it is 

 probable that respiration is also 

 a function of this organ, the 

 oxygen being taken into the 

 animal with the water which 

 diffuses through the body-wall, 

 FIG. 122. TWO species of RO- an <3 the carbonic acid beine cast 



[FERA. A. Phi'lnH,-nP R U..J., .,, "^ 



with the excretory fluid. 

 The body-cavity is not a true 

 ccelom. 



The sexes of rotifers are separate. The female possesses an 



ovary (Fig. I23> O vy) in which the eggs arise, a yolk-gland (vt) 



ch supplies the eggs with yolk, and an oviduct (ovd) which 



** /l.c 



after Hudson and Gosse.) 



br 



nph 

 ~- ^ 



oi> ovd 



m 



FIG. 123. -Diagram showing the anatomy of a ROTIFER 

 .V!^ f r 'i T 5 , C ''P reora1 ' and ^ Pastoral circlet of cilia ^ 

 eeler ^ ev" ^ fl Ioaca; /^/ dermic epithelium; d.f, dorsai 

 nth nenhridal'tnh' flame - Cel ' S ; l < intestine; m, muscles; mth , mouth; 

 npn , nephndial tube; ov, ovum; ovd, oviduct; ovy, germarium- bh 

 st, stomach; vl , vitellarium. (From Parker and HaswelT) 



