REPRESENTATIVE LAMARCKIANS 251 



arthropods, to adopt the Lamarckian views of which 

 he has been an exponent ever since. 



"Neo-Lamarckism," he writes, "gathers up and 

 makes use of the factors both of the St. Hilaire and 

 Lamarckian schools, as containing the more funda- 

 mental causes of variation, and adds those of geo- 

 graphical isolation or segregation (Wagner and Gu- 

 lick) , the effects of gravity, the effects of currents of 

 air and of water, of fixed or sedentary habits as op- 

 posed to active modes of life, the results of strains and 

 impacts (Ryder, Cope and Osborn), the principle of 

 change of function as inducing the formation of new 

 structures (Dohrn), the effects of parasitism, com- 

 mensalism, and of symbiosis, in short, the biological 

 environment ; together with geological extinction, nat- 

 ural and sexual selection and hvbriditv." 3 



Neo-Lamarckians, Packard affirms, do not mini- 

 mise the role of natural selection; they consider it as 

 a factor of prime importance whose action made itself 

 felt as soon as living things began to people the earth ; 

 but they endeavour to limit its sphere of influence. 



It is in the United States that Lamarckism has 

 won the greatest number of partisans, especially 

 among paleontologists. It is there only that La- 

 marckians form what can be designated as a school. 

 Everywhere else, Lamarckism has only scattered rep- 

 resentatives, considering as such those who really call 



3 Packard. Lamarck, The Founder of Evolution, p. 398. 



