XIV THE TRANSFORMATIONS OF THE ANIMAL WORLD 



vironment, and into the process of geologic changes. 

 Moreover, a great many features in Darwin's pic- 

 ture of the animated world were left by him either 

 entirely blank, or so slightly sketched that they 

 required filling in before even their outlines could 

 be grasped by any one whose attention had not till 

 then been given to their subject. Does the study 

 of fossils, for instance, offer us any example of a 

 regular chain of animal forms showing the gradual 

 transformation of one type into another ? Or, is 

 natural selection the only means that Nature em- 

 ploys to produce variations ? To such questions 

 the teaching of Darwin, as he left it, hardly sug- 

 gested an answer. 



To give a summary of the views on these and 

 other connected points that have achieved the 

 most success has been the task of M. Deperet, and 

 is one for which he is admirably fitted. In addition 

 to his high academical position, which has given 

 him much insight into the way in which these 

 subjects are regarded by untrained as well as by 

 trained minds, he has himself been an ardent worker 

 in the field of zoological evolution, and his publica- 

 tions on Les Animaux de Boussillon, Le Bassin de 

 Marseille, and Les Terrains de la Bresse are all 

 valuable contributions to the material evidence on 

 which the theory is based. Moreover, he has not 

 gone astray, as have so many German and some 



