THE BEGINNINGS OF LIFE. 19 



more fully discussed, and Dr. Carpenter laboured most 

 successfully to show c that so close a mutual relation- 

 ship exists between all the vital forces, that they may 

 be legitimately regarded as modes of one and the same 

 force 1 . 3 And he also maintained that these so-called 

 vital forces were evolved within the living bodies of 

 plants and of the lower animals by the transformation 

 of the light, heat, and chemical action obtained from 

 without, which were given back to the external world 

 again, either during the life of the living beings, or 

 after their death, in terms of motion and heat, and 

 also, to a slight extent, in the form of light and elec- 

 tricity. These doctrines are thus definitely expressed 

 by him 2 : c The vital force which causes the prim- 

 ordial cell of the germ first to multiply itself, and 

 then to develope itself into a complex and extensive 

 organism, was not either originally locked up in that 

 single cell, nor was it latent in the materials which 

 are progressively assimilated by itself and its descend- 

 ants 3 ; but it is directly and immediately supplied by 



1 In unicellular organisms, all the vital functions, so far as they are 

 differentiated, are carried on in the single cell ; and in the higher animals 

 which proceed from the growth and development of some single, equally 

 minute germ, specialization of function goes hand and hand with spe- 

 cialization of structure. 



2 Loc. cit. pp. 752-756. 



3 This holds good for plants, the lowest animals, and the initial 

 changes in the higher animals, though all the later vital manifestations 

 of the latter are dependent almost entirely upon the redistribution of the 

 forces pertaining to the organic substances which constitute their food, 

 and to the various chemical changes taking place within their own 



C 2 



