PRESENT STATUS OF THE QUESTION 9 



as Giard has pointed out, a clearer conception may 

 be obtained from an examination of the successive 

 introductory lectures of the courses in zoology at the 

 Paris Museum. Giard says : " It was the attentive and 

 minute study of the innumerable species of plants 

 which Lamarck, the botanist, had had to describe 

 and classify in the Flore francaise and Encyclopedic 

 methodique; it was the necessity of beginning, at the 

 age of fifty, a work of the same kind for the lower an- 

 imals ... ; it was finally the need of crowning with 

 a synthesis thirty years of analytical labours, which 

 led the great naturalist, till then a partisan of the 

 stability of the species, to demonstrate its variability 

 and to search for the causes of the transformation of 

 types." He then gives an extensive quotation from 

 the introductory lecture of 1806, from which the 

 following passage may be taken: 



"All the observations which I have gathered on 

 this important subject, even the difficulty which I 

 know, from my own experience, is now felt in dis- 

 tinguishing species in genera where we are already 

 very rich, a difficulty which is daily increased as the 

 researches of naturalists enlarge our collections, every- 

 thing has convinced me that our species have but a 

 limited existence and, for the most part, differ from 

 neighbouring ones only by shades which are difficult 

 to express. Those who have observed much and 

 have examined great collections, have been able to 

 convince themselves that, as the circumstances of 

 habitat, of exposure, of climate, of nourishment, of 



