CHAMBERS. 21? 



and Serres. In the first edition (p. 174), he rejects 

 Lamarck's hypothesis, "which has incurred much 

 ridicule and scarcely ever had a single defender," 

 on the ground that the arbitrary modification of 

 form by the needs of the animal could never have 

 led to the unities and analogies of structure which 

 we observe. On the previous page, he advocates 

 (without credit) St. Hilaire's modification of Buffon's 

 hypothesis of the direct action of environment. 

 Light, heat, the chemical constitution of the at- 

 mosphere, he says, " may have been the immediate 

 prompting cause of all those advances from species 

 to species which we have seen, upon other grounds, 

 to be necessarily supposed as having taken place " ; 

 he continues that these ideas are merely thrown 

 out as hints towards the formation of a just hypoth- 

 esis which will come with advancing knowledge. 

 He considers these natural laws as instruments in 

 working out and realizing all the forms of being 

 of the original Divine Conception. These views 

 were more definitely expressed in the tenth edition, 

 which appeared in 1853 (p. 155). Here he gives 

 as his final opinion that the animal series is the 

 result, first, of an impulse, imparted by God, 

 advancing all the forms of life, through the various 

 grades of organization, from the lowest to the 

 highest plants and animals. (This is the Aristote- 

 lian ' internal perfecting principle ' somewhat dis- 

 guised.) As this first 'perfecting' impulse would 

 evidently produce types not fitted to their environ- 



