No. 1791. 



SPERM TRANSFER IN DECAPODS— ANDREWS. 



429 



ing back from a terminal orifice, becoming bent posteriorly. The 

 mass sticks so tightly to the shell that a knife point does not separate 

 it. It cuts like hardened paste, cracking along the knife cut. It at 

 once suggests a coagulated mass containing a tubular cavity more or 

 less full of sperm on each side; that is, two more or less fused sperma- 

 tophores stuck to the shell. The two do not have their anterior 

 openings at the same level, as far as noted in several specimens, but 

 one is in advance of the other, and posteriorly one side is not like the 

 other. Moreover, the whole mass, though roughly of trefoil outline, 

 quite lacks the exact bilateral symmetry which would be expected 

 in any crustacean median organ, such as a real spermatheca. 



On removing a piece of the spermatophore and teasing it it was 

 found that the out- 

 ermost indurated 

 shell -like covering 

 incloses a some- 

 what softer friable 

 yellowish mass it- 

 self inclosing a 

 white - yellow rod, 

 or more or less 

 coiled filament, 

 quite different 

 from the rest of 

 the mass, being a 

 granular aggregate 

 of innumerable 

 rounded aggluti- 

 nated objects. Suf- 

 ficiently magnified 

 these are obviously 



sperm, rounded, 

 with a dark stain- 



FlG. 11.— SUTIFACE VIEW OF UNDER SIDE OF THOEAX OF A FEMALE 

 POLYCHELES SCULPTUS, SHOWING BASES OF LEGS AND LARGE PAIR 

 OF SPERMATOPHORES FUSED TOGETHER AND FASTENED TO THE 



ing central body shell between the last pairs of legs. 

 and outer film of 



protoplasm that presents various forms. In some it is projected as 

 pseudopodia-like processes. On the surface of the mass especially 

 these sperms send out clear films, as if actively amoeboid leucocytes. 

 Comparing these with the cells in the testes of the male we find that 

 these are smaller, the testes now being inactive, apparently, but the 

 cells in the deferent ducts are just like those in the spermatophores. 

 In this female the eggs in sections of the small H -shaped ovary 

 are apparently immature, which suggests that the sperm must 

 remain sometime in the spermatophore before the eggs are laid. 

 Other females show the eggs already fastened to the pleopods, includ- 

 ing the small first pair. 



