PRESIDENTIAL ADDRESS. 1,3 



multitudinous infinitesimal effects wrought by both of these 

 causes upon the form and character of organisms were 

 believed to be cumulatively perpetuated by heredity in the 

 modification of species and the production of new and altered 

 forms of vegetable and animal life. Prior to the date named 

 the few who conceived that existing forms might be modifica 

 tions of ancestral ones ascribed the changes wholly to the first 

 of these causes, the functional. Mr. Darwin showed that this 

 could not account for all cases, and in pointing out, simul 

 taneously with Mr. Wallace, the existence and mode of opera 

 tion of the selective agency he made the most important con 

 tribution yet brought forward to the science of biology. 



At the date of Darwin's death, 1882, the general doctrine of 

 evolution and the theory of development in biology had been 

 accepted by so nearly the entire body of scientific men that it 

 was scarcely worth the effort to conciliate the small remnant 

 who still adhered to the special creation hypothesis. The 

 only question was : By what agency or agencies is evolution 

 accomplished ? 



It would carry me too far to attempt to pass in review the 

 various theories of the pre-Darwinians Treviranus, De Mail- 

 let, Goethe, Buffon, Geoffroy St. Hilaire, Erasmus Darwin, and 

 the anonymous author of the Vestiges of Creation. This task 

 has been admirably performed by Professor Haeckel in his 

 History of Creation, and in the later editions of the Origin of 

 Species Mr. Darwin has collected quite a number of sporadic 

 adumbrations not only of the law of evolution itself but even 

 of that of natural selection. I shall be obliged to confine my 

 self almost exclusively to the one great mind, who far more 

 than all others combined, paved the way for the new science of 

 biology to be founded by Darwin, namely, Lamarck. His life 

 was chiefly devoted to the systematic and structural investiga- 



