LAMARCK'S THEORY OF EyOLUTION 235 



0(-.. •_/-'■ ' ' ' ''-'-' 



faculties, et?.,i is_£atirely the result of circumstances 

 to Jw]?.icJx the jace of each species has been subjected 

 by nature. If 



" I could prove that it is not the form either of the 

 body or of its parts which gives rise to habits, to the 

 mode of life of animals, but, on the contrary, it is 

 the habits, the mode of life, and all the influential 

 circumstances which have, with time, made up the 

 form of the body and of the parts of animals. With 

 the new forms new faculties have been acquired, and 

 gradually nature has reached the state in which we 

 actually see her" (pp. 12-15). 



He then points out the gradation which exists from 

 the most simple animal up to the most composite, 

 since from the monad, which, so to speak, is only an 

 animated point, up to the mammals, and from theni 

 up to man, there is evidently a shaded gradation in 

 the structure of all the animals. So also among the 

 plants there is a graduated series from the simplest, 

 such zs Mucor viridescens, up to the most complicated 

 plant. But he hastens to say that by this regular 

 gradation in the complication of the organization he 

 does not mean to infer the existence of a linear series, 

 with regular intervals between the species and genera : 



" Such a series does not sxis t ; but I speak of a series 

 almost regularly graduated in the principal groups 

 (masses) such as the great families ; series most as- 

 suredly existing, both among animals and among 

 plants, but which, as regards genera and especially 

 species, form in many places lateral ramifications, 

 whose extremities offer truly isolated points." 



This is the first time in the history of biological 

 science that we have stated in so scientific, broad. 



