250 THE THEORIES OF EVOLUTION 



although those scientists were not very familiar with 

 Lamarck's works. One of the first exponents of that 

 tendency, the very man who coined the word Neo- 

 Lamarckian, Packard, gives us a historical sketch of 

 Neo-Lamarckism in his book on Lamarck, which Mar- 

 cel Landrieu took as the basis of his book on the same 

 subject. 



Natural selection did not seem to the Neo-Lamarck- 

 ians an adequate explanation of evolution, as it does 

 not account for the origin of the variations which it 

 fosters. They preferred to attribute the origin of 

 those variations to the direct action of the environment. 

 A large number of books on comparative anatomy and 

 on paleontology were written from this point of view. 

 As early as 1866, A. Hyatt published a monograph 

 on fossil cephalopods in which he ascribed their suc- 

 cessive transformations to the action of the primary 

 factors of evolution, fixed by the transmission of ac- 

 quired characters. The same year appeared Cope's 

 book on the "Origin of Genera" written from the same 

 view-point. A few years later, in 1871, Cope con- 

 firmed his allegiance to Lamarckism, by recognising, 

 besides the action of the environment, the action of use 

 and disuse of organs. It is in his masterwork, "The 

 Primary Factors of Evolution," published in 1896, 

 however, that we find a complete expose of his system, 

 to which we devote a part of this chapter. 



In 1870, Packard was led by his observations on 



