15 



62. The diameter of the capsule of these sperms is about 

 3.8^ and the pseud opodia are some times as much as 7^ long* 



9. Sperms in the deferent duct. 



The mature sperms pass from the tuhules of the testis in- 

 to the deferent duct. The latter is a long extensively fold- 

 ed tuhe lined with glandular epithelium. The sperms form a 

 common mass when they enter this tube but the secretion form- 

 ed by its lining flows in amongst them and separates them in- 

 to groups. The secretion surrounding each group then hardens 

 and so forms a membrane, so that finally there are an immense 

 number of capsules containing the sperms. These capsules are 

 known as spermatophores. In this condition the sperms are 

 transferred to the seminal receptacle of the female crab. 



10. Summary and discussion . 



In this study of spermatogenesis in Menippe mercenaria 

 the principal points brought out are as follows: 



1. There is a single row of cells which persists on one 

 side of the testicular tubule and gives rise to successive 

 hatches of spermatozoa. 



2. The spermatogonia divide without the formation of a 

 spireme. The chromatin simply aggregates into chromosomes 

 which are then gathered into an equatorial plate. 



3. The maturation divisions follow one another quickly. 

 They are proceeded by spireme formation and a long period of 

 synapsis. 



