Foreword 



which distinguish themselves from their congeners by 

 some physical or psychological advantage relative to 

 the vital necessities of the environment, this advantage 

 having appeared by chance. 



The Lamarckian hypothesis assigned a primary 

 function to the influence of the environment, to the use 

 or disuse of organs; making the environment (at need) 

 even the origin of new functions and new organs. 



These two classical causes, perfectly reconcilable 

 or even complementary, necessarily implied the notion 

 of slow, imperceptible, and innumerable modifications 

 leading to the progressive formation of diverse species 

 from one or more primitive forms up to man. 



To these two general hypotheses, there have been 

 added in our day, countless secondary theories intended 

 either to establish special laws, such as those of heredity, 

 or to combat the ceaselessly renewed and multiplied 

 objections which a rigorous analysis of facts has brought 

 against the classical concept of transformism. 



Among these theories, some connect with Darwin, 

 some with Lamarck, others eclectically with both 

 systems. Some carry purely mechanical explanations; 

 others rise to dynamical concepts; a few even trench 

 on the domain of metaphysics. 1 



On all of them the same general judgment may be 

 passed: they show prodigious ingenuity and an even 

 more prodigious impotence. 



I shall not discuss these theories nor their claims 

 to explain the difficulties of transformism.* 



The innumerable arguments which have been in- 

 voked in various connections for or against transformism, 

 for or against the classic naturalism, relating as they 



1 Cf . specially Delage and Goldsmith : Les TMories de Involution 

 (published by Flammarion), and Deperret, Les Transformations du Monde 

 Animal. 



a Transformism. This term is advisedly used by Huxley to express 

 the general fact, as distinguished from particular concrete transformations 

 or abstract transformability. [Translator's note.] 



6 



