GENESIS OF MAN. 15 



due to this inheritable peculiarity, became thus a constant force 

 which, through the interbreeding of those possessing it, tended to 

 increase this variation, until in the course of generations it resulted 

 in differentiating the giraffe in the special attributes of length of 

 cervical vertebrae and of anterior limbs, and in giving it its present 

 anomalous position among antelopes. Instead of this, Lamarck says : 

 " With reference to habits it is curious to observe their results 

 in the peculiar form and figure of the giraffe {camelo-pardalis). 

 It is known that this animal, the tallest of the mammals, inhabits 

 the interior of Africa, and that it lives in places where the earth, 

 almost always arid and without herbage, compels it to browse 

 upon the leaves of trees and to be continually exerting itself to 

 reach them. From this habit, long maintained in all the individ- 

 uals of its race, it has resulted that its fore-limbs have become 

 longer than its hind ones, and that its neck has become so much 

 elongated that the giraffe, without rearing upon its hind feet ele- 

 vates its head and reaches to the height of six metres, (nearly 

 twenty feet)." 4 It will be observed how in this reasoning (and it is 

 so throughout), Lamarck passes from the observed fact directly to 

 the original cause, leaving out the intermediate steps which it is 

 necessary to supply in order to conceive of the manner in which 

 the results are produced. Now, it is precisely this part of the ar- 

 gument that mankind in general require before they are willing to 

 give in their adhesion to a theory. They say : " it all looks plau- 

 sible enough, but you fail to show us how it actually takes place." 

 As in his illustrations, so in his general " laws," Lamarck fails to 

 grasp the principle of Natural Selection. His first great law is 

 expressed in these words : " In every animal which has not passed 

 the limit of its developments, the frequent and sustained use of 

 any organ little by little strengthens, develops, and enlarges this 

 organ, and gives it a power proportionate to the duration of this 

 exercise ; while the constant failure to use such organ insensibly 

 enfeebles and deteriorates it, and progressively diminishes its capac- 

 ities, causing it finally to disappear." 5 His second law is as fol- 

 lows : "All that nature has caused individuals to acquire or lose 

 through the influence of the circumstances to which their race has 

 been long exposed, and consequently through the influence of the 



4 Phil. Zoo., Tome I, p. 254. Paris, 1873. 



5 Loc. cit., p. 235. 



