242 



r, i^j 



LAMARCK, TilS LIFE AND WORK 



to speak of the existence of a linear and regular series 

 of species or even genera : such a series does not 

 exist. But I speak of a quite regularly graduated 

 series in the principal groups, i.e., in the principal 

 system of organizations known, which give rise to 

 classes and to great families, series most assuredl}' 

 existing both among animals and plants, although 

 in the consideration of genera, and especially in that 

 of species, it offers many lateral ramifications whose 

 extremities are truly isolated points. 



" However, although there has been denied, in a 

 very modern work, the existence in the animal king- 

 dom of a single series, natural and at the same time 

 graduated, in the composition of the organization of 

 beings which it comprehends, series in truth neces- 

 sarily formed of groups subordinated to each other 

 as regards structure and not of isolated species or 

 genera, I ask where is the well-informed naturalist 

 who would now present a different order in the ar- 

 rangement of the twelve classes of the animal king- 

 dom of which I have just given an account ? 



" I have already stated what I think of this view, 

 which has seemed sublime to some moderns, and in- 

 dorsed by Professor Hermann." 



Each distinct group or mass of forms has, he says, 

 its peculiar system of essential organs, but each organ 

 considered by itself does not follow as regular a course 

 in its degradations (modifications). 



" Indeed, the least impol-tant organs, or those least 

 essential to life, are not always in relation to each 

 other in their improvement or their degradation ; and 

 an organ which in one species is atrophied may be 

 very perfect in another. These irregular variations 

 in the perfecting and in the degradation of non-essen- 

 tial organs are due to the fact that these organs are 

 oftener than the others submitted to the influences 



