9. THE REPRODUCTIVE SYSTEM 



97 



The spermatophores 



The spermatophores represent thin-walled elongated packets containing 

 the sperm. In the Athecanephria they are spindle- or cigar-shaped (Fig. 

 65A) and in the Thecanephria they are leaf-shaped (Fig. 65B) (Ivanov, 

 1957a). Their size varies in rough accord with the size of the animal. Thus in 

 Siboglinwn minutum the spermatophores are no more than 120/x long, while 

 in Spirobrachia grandis they reach 2-5 mm. The shape and size of the sperma- 

 tophores make good specific distinctions (Ivanov, 1952, 1957a). 



A long thin filament is attached to one end of the envelope of the sperma- 

 tophore and folded up into a tight skein which lies on the surface of the 

 spermatophore (Fig. 65). It seems possible that the filament unwinds when 

 the spermatophore is released into the water and serves as a flotation device, 

 or it may become entangled in the tube of the female. The walls of the 

 spermatophore contain much polysaccharide. 



[It seems to me unlikely that either of the suggestions put forward by 

 Ivanov for the function of the filament of the spermatophore represents the 



A 1 



Fig. 65. Spermatophores. A - Siboglinum fedotovi; В - Lamellisabella johanssoni. (After Ivanov, 

 1957a.) 



