i So THE MAIN CURRENTS OF ZOOLOGY 



in his work the summation of the protoplasm idea 

 and the reform of the cell-theory. The effect of 

 these two conceptions on zoology cannot be over- 

 estimated. Taking rank with the greatest dis- 

 coveries of the nineteenth century, their direct 

 application in zoology have been of supreme value. 

 Schultze (1825-1874) also founded one of the most 

 influential periodicals of zoological science, the 

 Archil) fur Mikroscopische Anatomie. 



10. Mendel. Since 1900, the date of the redis- 

 covery of alternative inheritance and purity of the 

 germinal elements, Mendelian inheritance has been 

 one of the most actively pursued of biological topics. 

 Mendel (1822-1884) made his chief observations on 

 plants and published the same in 1866-1867, but, 

 the study of Mendelian inheritance in animal forms 

 has exerted such a great influence, that his name is 

 properly embraced in this list. On the basis of 

 strictly scientific output and commanding intel- 

 lectuality there are other names that would contest 

 the position with Mendel, but, on the basis of the 

 wide influence of his happy discoveries, he is entitled 

 to rank with the men whose work has stimulated 

 zoological investigations and been of the widest 

 influence. 



