EVOLUTION AND MENDELISM 225 



was the common ancestor of all ungulates had not only the 

 factor for producing horse-like molars, and the factors for all 

 the intermediate stages, but at the same time the factors for 

 producing molars such as are met with in the ox, the rhinoceros, 

 the titanothere, the tapir, and the elephant ? Had it also the 

 factors for the antlers of the deer, for the trunk of the elephant, 

 and for the loss of the hind limbs in the dugong, in addition to 

 the factor for the fineness of merino wool ? 



The old views of Lamarck and Darwin may require slight 

 amendment here and there, but they certainly have too much 

 established truth to be ever altogether set aside. I quite 

 agree that those zealous ultra-Darwinians who have en- 

 deavoured to explain all evolution by the working of natural 

 selection have done much to discredit the theory. But apart 

 from the undue importance placed on natural selection by 

 Darwin and his followers, there is no doubt that most of Darwin's 

 work will stand the test of time. 



Lamarck appears to have been the first scientist who 

 clearly recognised the importance of the part played by the 

 use and disuse of organs in the modification of animal types ; 

 and a large number of workers since his time have agreed that 

 in function we have a prime factor. Darwin considered it 

 played a secondary part, and there have been those who have 

 argued that it played no part at all. Even now there are many 

 who hold, with Bateson, that the actions and habits of an 

 animal cannot produce any changes which can be inherited by 

 the offspring. They are willing to admit that the increased use 

 of a limb will result in the increase of the muscles and of the 

 strengthening of the bone in the individual, but they refuse to 

 admit that the next generation will be influenced even in the 

 slightest degree by the action of the parent. I do not know 

 what are Bateson 's reasons for refusing to admit that acquired 

 modifications can be inherited, but it has long seemed to me 

 that the arguments of the opponents of the theory amount to 

 this, that they cannot see how the sexual elements of an animal 

 can be influenced by the habits of the animal, therefore they 

 cannot be. 



Those of us who hold that the actions of an animal do 

 influence the next generation do not undertake to prove it 

 experimentally. If it took 3,000,000 years or 1 ,000,000 genera- 

 tions to evolve the molar of the horse from the molar of Hyraco- 



