444 The Animal Kingdom 



two projections of the epidermis, the lemnisci. These may function 

 as fluid reservoirs for the retraction of the proboscis. 



The sexes are separate, with the male being generally smaller 

 than the female. In the male, a pair of large testes develop. These 

 are contained in a prominent genital ligament which extends from the 

 proboscis receptacle. The sperm pass from the testes through a duct 

 to the posterior genital pore which is contained in a large bell-shaped 



P/vboscis 



Recepfade- 



of neck i"« 



Behachrs of- 



lemniscus 



Brain 

 Hefinacuhm 



--beniM 

 ligarrKfjt 



- Tesfi's 



-Jesh's 



Cemenf" 

 glandi 



■rd. — Bursa 



Fig. 144. — Anatomy of an acanthocephalan, Acanthocephalus. (By permission from 

 Invertebrate Zoology by Van Cleave, 1931, McGraw-Hill Book Company, Inc.) 



bursa. The distal end of the sperm duct is modified into the cirrus 

 which is, of course, located in the copulatory bursa. The male also 

 has a group of cement glands just posterior to the testes which like- 

 wise communicate with the sperm duct. 



The female has no permanent ovary, egg masses are formed and 

 become fertilized. The eggs develop large individual embryos which 

 are surrounded by embryonic membranes. In a fully gravid female. 



