330 



ESSENTIALS OF ZOOLOGY 



this function, however, is performed by the branched enteron. It is 

 significant that the reproductive system upon which the continuance 

 of the race depends is highly specialized, this succeeded by the diges- 

 tive system responsible for nourishment of the individual, and this 

 followed by the nervous system which relates the organism to its 

 surroundings. 



Aurick 



CerebraL 

 (janglion 



Lonqibudinal 



nerve cord 



Testis 



Vasa X-? 



efferentia 



interal 

 nerve 



Vas 



deferens 



Mouth \-^^^ 



Seminal 



vesicle 



Sewlnaf 



{receptacle 



_\ Ovary 



^^Yolkcjlands 



Lateral nerve 



Jniestine 

 Diverticula 



<c:^-^ lumen of 



pharynx 



__/nfccjfc/ne 

 Oviduct 



J^aryn(jcal 



chamber 



^.Qen'italpore 



Fig. 119. — Reproductive system of planaria. Male organs are shown on one side 



only. 



