THE NERVOUS TISSUES. 185 



mixture of Ehrlich's hematoxylin i vol. , glycerin i vol. , and i % chloral hy- 

 drate solution 6 vols. , in which the specimens are allowed to remain for from 

 three to ten days. The pieces are now placed in glycerin acidified with 

 acetic acid (solution No. i), in which the color becomes differentiated, 

 the nerves and nerve-endings in the muscles and vessels being deeply 

 stained, while the remaining portion of the specimen becomes decolor- 

 ized. After having stained with No. 2, the pieces may be preserved in 

 pure glycerin, to be treated later with acetic acid (solution No. i). 



These methods are most successful in reptilia and mammalia, more 

 difficult in the other classes of vertebrate animals. 



