NO. 1791. 



SPERM TRANSFER IN DECAPODS— ANDREWS. 



431 



of the female is not elevated as is the region toward the fourth legs, 

 fig. 11. Here the spermatophoral mass seems more clearly a mere 

 applied mass of secretion containing two sperm strands. In this 

 posterior region the strands of sperm are bent, as dimly seen in fig. 

 11, and hence they appear elongated in cross section, fig. 13. The 

 strand on the left of the figure shows that there the sperm does not 

 completely fill out the tubular cavity in the secreted spermatophore, 

 but that there is some other secreted material inserted here between 

 the general walls of the spermatophore and the actual sperms. 

 Probably there is a slight admixture of sperm and secretion such as 

 occurs toward the end of the filling of the spermatheca in Cambarus. 

 In the main each spermatophore is a long bent rod of sperm 

 inclosed in a thick envelope of some translucent secretion and stuck 

 fast to the sternum of the female along with a like spermatophore. 



Fig. 13.— Cross section posterior to that shown in pig. 12. 



That these two spermatophores arise from the deferent ducts of 

 one male seems probable from the following observations on the male 

 of this same species. 



In a male from the last-mentioned locality the brown mass pre- 

 viously mentioned as proceeding from the orifice of the male duct, 

 fig. 14, is found on cutting off the leg to run throughout the base of 

 the leg as a large rounded cylinder up into the body of the male. 



The part of this mass that projects into the water is seen in fig. 14 

 as the dark bent object above, while its continuation from the base 

 of the leg into the body is represented as cut across below." Following 

 this up into the body we find the colored cylinder continues as a cast 

 of the deferent duct for a distance of 25 to 30 mm. and with a width 

 of 2 mm. to end abruptly at the relatively small and delicate lobulated 



o- The dark-colored protuberance is more than 2 mm. long, not the same exactly on the 

 right as the left leg, of cylindrical form but flattened so that one diameter is 2 mm. and 

 the other about 1.5 mm. It bends at the tip as if to coil, and is somewhat retort 

 shaped. The white contents seen throughout the translucent colored part comes to the 

 tip and is there closed off as if by the elasticity of the inclosing secretion. 



