268 the president's address. 



as a matter of mere convenience, speak of vital forces also. 

 Indeed, it appears to me more in accord with scientific method 

 to do this than to ignore the existence of such characteristic vital 

 phenomena as our own consciousness and intelligence or leave 

 them to be explained by supernaturalism. 



After all, the quarrel between the vitalist and the mechanist is 

 chiefly over mere terminology. The vitalist knows perfectly well 

 that the organism may to a very large extent be looked upon as 

 a machine in which chemical and physical processes are utilised, 

 and the mechanist knows equally well that he cannot hope to 

 explain his own consciousness, and his own intelligent action, 

 in terms of chemistry and physics. If we recognise these two 

 facts it is a matter of comparatively small importance to decide 

 in what terms the unknown factors can best be described. 



At any rate I see no reason why vitalists and mechanists should 

 not agree that living organisms first arose, either on our own 

 planet or elsewhere, by means of a complex process of physico- 

 chemical synthesis, in which the electron, the atom, the molecule, 

 the colloidal mult i- molecule and the simplest protoplasmic unit, 

 may be taken as representing the chief stages. This at any rate 

 is what we should expect from the study of those analytical and 

 synthetical processes with which the bio-chemist has familiarised 

 us, and from what we know of the process of evolution in 

 general. 



What may be the nature of the simplest protoplasmic unit is a 

 question still under discussion. That it is not what we commonly 

 call a cell seems certain, for a cell has a complex structure which 

 must have been preceded by something very much simpler. The 

 differentiation into cytoplasm and nucleus, and, above all, the 

 extraordinarily complex phenomena of mitotic division, which are 

 observable in nearly all cases where a distinct nucleus is present, 

 can only have been attained as the result of a long process of 

 evolution. The existence of the Bacteria, in which, although 

 both cytoplasm and chromatin may be present, there is still no 

 properly defined nucleus, perhaps indicates one phylogenetic stage 

 through which the fully developed cell may have passed. 



Possibly few biologists of the present day conceive of the most 

 primitive organisms as relatively large unnucleated masses of 

 structureless protoplasm, such as some of Haeckel's famous 

 Monera were supposed to be. " The entire body of these 



