EVOLUTION xxxiii 



consideration believed in a greater mutability than has been 

 found to be the case. Lamarck believed that an alteration 

 of the environment would within a few generations effect a 

 permanent alteration in the structure of a species. Of 

 this I shall adduce a number of instances in the following 

 section. He perceived how easily domestic races evolved 

 out of wild species ; but he apparently did not know how 

 easily they also lapsed into the wild state ; nor that varia- 

 tions, so conspicuous to the eye, are highly unstable and 

 superficial. By reaction against the doctrine of the per- 

 manent stability of species, he adopted an altogether exag- 

 gerated view of their instability. Indeed, his views on this 

 subject are scarcely consistent : and Sir Ray Lankester 

 has already urged that his first and second laws are 

 incompatible. 



Given the fact of evolution, the question at once arose as 

 to what are the physical causes of it. Of natural selection 

 Lamarck had not the slightest conception. The only passage 

 that is even remotely suggestive of it, is when he deplores 

 the inequality of intellectual capacity among men ; for 

 those with higher intellects gain an advantage over the 

 others, and hence these others, constituting the great 

 majority, must suffer. He regarded the equalisation of 

 intellectual capacity as the greatest social reform required. 

 It is plain how little he guessed at the theory of natural 

 selection. 



He held that evolution was due to the co-operation of 

 two factors. The first and most fundamental was due to 

 an innate tendency to evolve towards increasing complexity 

 of structure : this tendency being conferred upon the low- 

 liest animals at the moment of their spontaneous generation. 

 I shall describe Lamarck's opinion as to the physical causes 

 of the tendency, as also of spontaneous generation itself, in 

 a later section deaHng with his physiology. For the present, 

 it suffices to observe that Lamarck beheved that various 

 portions of inorganic matter are constantly being vitalised 

 or endowed with life by a process of spontaneous generation, 



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