194: A. A. MERLIN ON THE SPERMATOZOON OF THE RAT. 



axial cone from an oil-immersion condenser, one is strongly- 

 impressed with the conviction that what is seen is merely a 

 partial resolution of really existing organised structure, which 

 increase of aperture would more fully reveal. 



It has been pointed out by biologists that protoplasm is fre- 

 quently so much affected by the staining and fixing reagents 

 employed as to coagulate, and give rise to false structural 

 appearances. This may be the case in some instances, but it 

 has yet to be shown that idefinite features of the kind figured 

 in connection with this paper can be thus constantly and 

 recurrently reproduced. The likelihood of a merely chemical 

 action being responsible for the production of such decidedly 

 structural effects would seem lo be very remote indeed ; otherwise 

 little reliance would be placed by many on much of the beautiful 

 and elaborate work which has been accomplished in recent times 

 in connection with the mitotic division of the cell. 



Jour a. Quekett Microscopical Club, Sir. 2, Vol. VIII., No. 50, April 1902. 



