MODERN BIOLOGY 32.9 



finally, Cuvier, with whom he was so often in controversy, has undoubtedly 

 exercised great influence upon him through his earlier writings; we have 

 already seen how Lamarck gained from them important ideas in regard to 

 classification, but in connexion also with problems of evolutionary history 

 he has undoubtedly felt the influence of his younger rival — a point that 

 will be more closely dealt with in connexion with the latter's own work. 

 But though we can thus trace outside influences in Lamarck's speculations, 

 it is nevertheless to his lasting credit that he formulated and elaborated as 

 he did the idea of origin. In that respect he is truly a pioneer of modern 

 biology. It is true that the theory of the heredity of qualities acquired 

 through the influence of environment has not stood its ground in face of 

 modern exact research in this field, and also that the actual method of work- 

 ing out the idea leaves very much to be desired. Thus, for instance, one would 

 have expected that when he so definitely differentiates between essential 

 and non-essential organs and qualities, he would have tried, following his 

 own method, to trace the development of the essential organs (heart, lungs, 

 backbone), instead of dilating upon such details as the legs and feet of waders 

 and swimming birds. But the idea itself is nevertheless conceived and elab- 

 orated not only with splendid consistency, but also with a keen eye for pe- 

 culiarities in the interrelation of living forms, which left all his predecessors 

 far behind. And indeed details can be instanced which are highly original, 

 as, for example, the theory of the origin of the digestive canal through in- 

 vagination. It is in all probability here that Haeckel, the originator of the 

 "gastr^a" theory and an enthusiastic admirer of Lamarck, obtained the 

 idea for his hypothesis, which has proved so valuable to modern embryology. 

 The superficiality of Lamarck's psychological speculation has already been 

 pointed out, but this quality he shared with many of his predecessors and 

 contemporaries; he is here a child of the era of enlightenment; the Supreme 

 Originator who was at one time creative, but afterwards inactive, and 

 also the subsequently omnipotent nature, are ideas that, since the days of 

 Voltaire, often recurred in the works of scientists of that epoch, while even 

 the mechanical soul-theory constantly occurs, better or worse expounded in 

 the writings of that period. In the purely systematical sphere, on the other 

 hand, Lamarck is, as previously pointed out, one of the foremost of all time, 

 and perhaps he has made in this sphere his most lasting, although not his 

 most brilliant, contribution to the development of biology. 



Importance of Lamarck's life-work 

 We have already suggested that Lamarck's reputation in his own age was 

 based entirely on his work as a systematist. That he did not receive recogni- 

 tion as a natural philosopher was essentially due to the fact that his materi- 

 alistic conception of nature, which originated during the previous century, 

 was already out of date when he came on the scene; the two scientists who 



