THE CELLULAR CHANGES OF AGE 51 



them branched so as to better receive and collect the 

 impulses ; one of them remained single and very much 

 elongated, and acquired a somewhat different structure 

 in order to serve to carry the nervous impulses away. 

 The third picture 1 shows us a section through the 



FIG. 12. A LARGE CELL FROM THE SMALL BRAIN (CEREBELLUM) OF A 

 MAN. It is usually called a Purkinje's cell. It was stained black throughout 

 by what is known as the Golgi silver method, hence shows nothing of its 

 internal structure. After von Kolliker. 



spinal cord of an adult fish. It has been treated by a 

 special stain in order to show how certain elements of 

 the spinal cord acquire a modification of their organisa- 

 tion by which they are adapted to serve as supports 

 for the nervous elements proper. They play in the 



1 The illustration referred to is not reproduced in the text. 



