52 Biological Stains 



as to the possibility of dyes becoming histochemical reagents (see 

 Conn, 1925), but nothing like the present development of histo- 

 chemistry was then forseen. Histochemistry, although a fascina- 

 ting field from the theoretical standpoint, is neither the outgrowth 

 of the general chemical theory of staining, nor does it prove the 

 truth of the latter as a sole explanation of staining. 



