210 



THE ANIMAL KINGDOM 



Figure 11.7. Dugesia copulating. (After Hyman.) 



Testes 



Sperm 

 du-ct 



Ova.T'y 

 i Seminal Ttc<z,p\eL.c[z. 



IPV" Vitelline glands 



Ovovitelline dxzct 



"Copulatoi-y sac 



Penis bixli) 



Sperm duct ■ 

 Ovovitelline duct-" 



Penis 



Atrium Geriitalpore 



B 



Figure 11.8. Reproductive system of Dugesia. A, A dorsal view showing the male 

 organs on the left and the female organs on the right. B, A side view of the copulatory 

 organs. (After Hyman.) 



away from each other with the posterior regions elevated and their 

 ventral surfaces pressed together (Fig. 11.7). On the ventral surface, 

 posterior to the mouth, is the genital pore. Each individual protrudes 

 a muscular penis through its pore and through the pore of its mate into 

 a copulatory sac (Fig. 11.8). Sperm that have been produced in the 

 many testes and stored in the sperm ducts leading from the testes to 

 the penis bulb now pass into the bulb where they are mixed with se- 

 cretions of the bulb, and are then forced by muscular contractions 

 through the penis into the sac of the mate. Secretions of the penis bulb 



