1360 Journal of Applied Microscopy 



proved of more value. After staining tissues in a concentrated solution of 

 ammonium picrate (which I used in sea water) the material is brought into the 

 following solution : 



Ammonium molybdate, - - 1 gr. 



H^O, ; . - - - "g'-loriUccH^O. 

 oper cent, osmic, - - - lU gr. ) ^ 



Peroxide of hydrogen, - - 1 gr. 



or (with somewhat better results for tunicates), phosphomolybdate of soda may be 

 substituted in the above formula for the ammonium molybdate. 



After 3^ to 1 hour in above solution (or 4 to I'J hours in the osmic solution), 

 we wash in water, rapidly pass through the alcohol, xylol, and imbed in paraffin. 

 Results from this method have not been uniformly successful. 

 De Witt Clinton High School, N. Y. C. GeorGE William Hunter, Jr. 



Spermatozoa of Man, Domestic Animals, and Rodents. 



The male cell, or spermatozoon, is of minute size, and in its locomotor 

 energy and vitality resembles a flagellate monad. Anatomically it is a true cell, 

 consisting of the " head," composed mainly of nucleus, and the motile " tail," 

 which may be fibrillated, and a small central portion between the head and tail, 

 which is sometimes regarded as the " centrosome." 



In studying the spermatozoon of the mastifif, I noticed the striking resem- 

 blance it bore to that of man ; finding that if the spermatic fluids were allowed to 

 stand for a time, even staining did not furnish sufficiently satisfactory evidence 

 to enable one to distinguish, beyond question, the spermatozoon of man from that 

 of the dog, except where careful measurements were employed ; and a fact ever 

 to be borne in mind is, that these measurements may vary slightly in different 

 persons and animals, and even in the same specimen. 



Through the courtesy of Dr. James Johnston I secured testicles, preserving 

 as much as possible of the vasdeferens, from animals slaughtered at the Phila- 

 delphia abattoir, to which collection was added those from certain animals 

 employed for experimental work in the laboratory. The spermatic fluids studied 

 were taken from the vasdeferens, and from an incision of the testicle. In man, 

 the fluid ejaculated at intercourse was also studied and the findings compared 

 with those where the fluid was taken from the vasdeferens and from the paren- 

 chyma of the testicle. 



Examinations were made immediately after the testes had been removed, and 

 on the first, second, third, fourth, and fifth days after their removal. Spermatic 

 fluids thus collected were placed in cold water, after which it was found that the 

 tails became coiled, and were soon detached from the heads. In no case were 

 the spermatozoa found to possess individual movement twenty-four hours after 

 the testicle had been removed, or after the death of the animal ; nor were they 

 ever found motile in man even a few hours after death. These findings differ 

 from the statements often made, that spermatozoa remain active for a long time 

 after the death of the animal. To determine this point one testicle was kept in 

 a cool room, and the other at a temperature of about 75° Fahr., when certain 



