32 



Efforts were made to reverse this process ty placing the 

 sperms In very concentrated solutions of the salts used. The 

 only effect of this treatment was a shrlnkihg of the everted 

 portion, which would again swell up and the process of eversion 

 continue when dilute solutions were again used. After the 

 explosion had reached the stage presented in Pig. 8E the only 

 part affected by concentrated solutions was the protoplasmic 

 portion at the bottom. It is also true that this is the only 

 part that takes methylene blue, methyl green or thronin 

 stains when these are applied to the living sperms. It was 

 rather surprising that the contents of the everted capsule 

 were not stained by these stains. Sometimes a few granules 

 can be seen in this cavity. 



Figures 73, 74, 84 and 85 were made from sperms that had 

 been kept in a 5% KUO3 solution for 51 days. We observe here 

 that partial explosion had taken place. Those shown in Figs. 

 84 and 85 had reached the stage corresponding to Fig. 70. 

 When these were treated with a solution of lower concentration 

 the eversion continued but the wall of the part already evert- 

 ed seemed to be hardened so that it made an elongated collar 

 through which the further inversion took place. 



6. The effect of reagents on the everted sperms. 



After trying several fixing reagents it was found that 

 for imbedding and cutting the crab's eggs Morgan's fluid gave 

 decidedly the best results. This fluid is a saturated solu- 

 tion of picric acid in ^0% alcohol, to 100 c.c. of which 2 o.c. 

 of H2SO4 are added. Sperms in various stages of the process 



