DISTRIBUTION OF SUBSTANCES IN SPERMATOZOON. 249 



blue, are much clearer than the preparations mounted in balsam, 

 and particularly after treating with xylol. 



m.p. 



FIG. 9. Spermatozoa of Arbacia prepared according to method B of Schumacher 



and stained in Victoria blue. 



Summarizing the facts obtained by the method of Schumacher, 

 one can say that in the structure of the spermatozoon there are 

 free lipoids and lipoproteids which are located normally in the 

 tail, middle piece, and acrosome. The facts described in I and 3, 

 connected with the facts observed in living spermatozoa, demon- 

 strate that the lipoids and lipoproteids of the tail are located 

 on the surface. 



4. OSMIC ACID (i PER CENT. AQUEOUS SOLUTION 24 HOURS* 



OR 2 PER CENT. AQUEOUS SOLUTION FIXING 



BY VAPOR 1-5 MINUTES). 



Osmic acid shows in Arbacia very similar pictures to those 

 obtained by the lipophilic stains. One can see very clearly the 

 basal ring, the tail, the middle piece; the conical part of the 

 head appears darkened and unburnished, which gives us the 

 impression that the substance darkened by osmic acid is located 

 on the surface of the spermatozoon. The substance between 

 spermatozoa is darkened too. On fresh preparations this sub- 

 stance can be distinguished still more clearly. If spermatozoa 

 are shaken in sea- water, and from the clear fluid, which separates 

 in the upper part of the test tube, a drop is taken and submitted 



