LAMARCK ON THE "APE QUESTION." 8? 



increased use of its organs, and to the fact that it trans- 

 mitted the improvements thus acquired to its descend- 

 ants. Lamarck considered the most important of these ad- 

 vantageous variations to be the erect gait of Man, the differ- 

 ing form of the hands and feet, the growth of language, 

 and the correlative higher development of the brain. He 

 assumed that the Apes most closely akin to Man, those 

 which became the ancestors of mankind, made the first 

 step toward becoming human when they gave up the habit 

 of climbing and living on trees, and accustomed themselves 

 to an upright gait. This resulted in the carriage peculiar 

 to Man and in the reconstruction of the spinal column and 

 pelvis, as well as in the specialization of the two pairs of limbs 

 the fore pair developing into hands for the purpose of 

 grasping and touching, while the hind pair were used only 

 for walking, and thus developed into true feet. In con- 

 sequence of the totally changed mode of life and of the 

 correlation and interrelation of the various parts of the 

 body and their functions, important changes occurred also 

 in other organs and their functions. The change of food, 

 for example, caused a change in the jaws and teeth, and, 

 consequently, in the entire formation of the face. The tail, 

 no longer used, gradually disappeared. As these Apes lived 

 together in societies and acquired regulated family relations, 

 such as are still found among the higher classes of Apes, the 

 social habits, or so-called " social instincts," were especially 

 developed. The Ape's language of mere soimds grew into 

 the word-language of Man, and abstract ideas were accu- 

 mulated from concrete impressions. The brain gradually 

 developed in correlation with the larynx ; the organ of the 

 mind in interrelation with that of speech. These important 



