66 Scientific Intelligence. 



With the advance of scientific knowledge others have discov- 

 ered laws, regarding the processes of evolution, which were dis- 

 tinctly formulated by Lamarck, and it is the full exposition in 

 English of Lamarck's own view upon evolution that constitutes 

 the chief value of this volume. Although readers will still differ 

 as to the place Lamarck deserves among the founders of the mod- 

 ern theory of evolution, the reading of his words clearly demon- 

 states that he had in mind the construction of a fully elaborated 

 scheme of factors to account for the modification of organic 

 beings by slow and gradual variation into the diverse organic 

 species now living on the earth. The Lamarckian factors use and 

 disuse, effort (or felt-want or need), direct effect of environme?it 

 and inheritance of acquired characters are recognized forces 

 at work in determining organic variation. There can be little 

 doubt, also, that growth force, which Cope has named Bathmism, 

 is a factor of varying, in so far at least as varying is a normal 

 function of all living and therefore growing bodies. These fac- 

 tors, however, without natural selection, do not constitute a com- 

 plete scientific theory of organic evolution. 



In the preface, the biographer states that "For over thirty 

 years the Lamarckian factors of evolution have seemed to me to 

 afford the foundation on which natural selection rests, to be the 

 primary and efficient causes of organic change, and thus to 

 account for the origin of variations which Darwin himself 

 assumed as the starting point or basis of his selection theory" 

 (pr. vii). 



But may it not also be said that before Darwin no theory 

 of evolution ever succeeded in crossing the line between philo- 

 sophic speculation and natural science ? The theory of natural 

 selection first won for evolution a place among the sciences. 



At first Lamarck believed that species were constant in nature, 

 but as he tells us in the appendix to " Systeme des Animaux sans 

 Vertebres" (written probably as late as 1801), " I am now con- 

 vinced that I was in error in this respect, and that in reality only 

 individuals exist in nature " (p. 249), " all the modifications that 

 each living being will have undergone as the result of change of 

 circumstances which have influenced its nature will doubtless be 

 propagated by heredity (generation). But as new modifications 

 will necessarily continue to operate, however slowly, not only 

 will there continually be found new species, new genera, and 

 even new orders, but each species will vary in some part of its 

 structure and its form " (p. 250). 



It was, however, not till the appearance of the " Origin* of 

 Species ? ' that a scientific way of accomplishing this result was 

 discovered. It is natural selection which explains how it is that 

 organisms varying by whatever means, can have their characters 

 preserved when favorable, — rejected when useless, and thus indis- 

 criminate variability can be reduced to the systematic evolution, 



