SPERMATOGENESIS. 



1. The Testis. 



The testis of Menlppe Is a large paired organ lying Just 

 underneath the dorsal wall of the carapace. The Inner ends 

 of the right and left portions lie close together Just anter- 

 ior to the heart and from here diverge anteriorly and later- 

 ally to the outer edge of the carapace. It is composed of 

 relatively long and complexly folded tubules which vary in 

 diameter from 0.14 to 0.33 mm. The deferent duct, one on 

 each side, leads from the testis to the base of the last 

 thoracic leg. It is extensively convoluted so as to form 

 two large masses, one lateral to the posterior part of the 

 testis and the other beneath the posterior part of the heart. 

 The deferent duct is lined with a layer of columnar epithelium 

 which secrets the substance that forms the walls of the 

 spermatophores . 



2. Methods . 



Pieces of the testis, obtained by cutting across the 

 organ, were fixed in Worcester's fluid. This is a saturated 

 solution of sublimate in 10^ formalin. Other fixing fluids 

 were used but did not give as satisfactory results. The sec- 

 tions were cut Iji to lOjx thick. The stains used were thionln 

 and eosin, safranin and LichtgrUn, iron-haeraatoxylln, and 

 Delafleld's haematoxylln. 



