DISTRIBUTION OF SUBSTANCES IN SPERMATOZOON. 243 



which touches it: granules, slide, cover slip, eggs, or to another 

 spermatozoon. Frequently it sticks to the tail of the same 

 spermatozoon. 



Victoria blue or Fuchsin in sea-water solution: These sub- 

 stances are very feebly soluble in sea-water; but if we keep 

 an excess of stain for several hours in sea-water, a weak solution 

 is obtained in which the spermatozoa can live for ten to thiity 

 minutes and one can see the changes which occur more easily 

 than in distilled water solution. 



FIG. 6. Spermatozoon of Arbacia showing sensilla amoeboidea. 



The regions of the spermatozoon already mentioned take the 

 color. But for a short time there is a slight stain on the surface 

 of the head also, before the middle piece is stained. After a 

 variable time the head loses the color gradually and one can 

 see a slow enlargement of the middle piece and the formation 

 of delicate protoplasmic filaments therefrom, which move spo- 

 radically. These deserve a more precise description. 



The basal part of the head has the appearance of a ring, 

 somewhat thicker than the rest of the head. When the sperma- 



