INTROD.] THEOEIES OF LIFE. 19 



with success in forming some organic products by artificial means. 

 (See p. 9). 



And let it not be forgotten that the living laboratory of the ani- 

 mal and plant is one well stored with means for analysis and syn- 

 thesis : the continual introduction of new material gives full scope 

 to the play of chemical affinity, and at every point the constant 

 attendants of chemical action, heat and electricity, are developed. 

 May it not reasonably be inferred that these agencies, which the 

 chemist can so readily turn to account in his artificial processes, are 

 not idle in the work of combination and decomposition in the living 

 body? A great difference as to sensible qualities, in the various 

 organic products, by no means implies great difference of chemical 

 constitution, for it is well known that the addition or removal of a 

 single atom of one of the ingredients of any compound is sufficient 

 to produce a substance with totally new properties ; and such is 

 the complex nature of organic molecules, that the attraction be- 

 tween their component elements yields readily to disturbing 

 causes. 



But how shall we explain the strange process of organization, in 

 the production of that infinite diversity of forms, that " insatiable 

 variety of Nature/' which is so conspicuous in the vegetable and 

 animal kingdoms ? Must we imagine the creation, in corresponding 

 number and variety, of a duplicate order of beings, whose duty it 

 shall be to preside over the development of each species, and to 

 impress each with its peculiar characters ? Or does it not seem 

 more consistent with that grand simplicity, which the phenomena 

 of nature everywhere present, to suppose that the organization of 

 animals and plants, in such great variety, is the result of the 

 primary endowment of organic matter, at the creation of the first 

 parents of each species, by the Almighty ? The animal or vegetable 

 matter of each species was created to propagate after a certain 

 fashion, and after that only; the organic cells, of which these 

 organisms consist in the early stages of development, have the 

 power of evolving the adult tissues of animals and plants of their 

 own species only; the simple volvox develops, from its interior, 

 organic cells which become volvoces ; and the cell which forms the 

 ovum of the elephant or the mouse, is able, by an inherent power of 

 multiplication, to evolve the skeletons and organs of each of those 

 animals respectively. 



The peculiar endowments of the organic matter, composing the 

 various tribes of animals and plants, are transmitted from parent to 

 offspring. But they admit of certain modifications under the influ- 



c 2 



