28 



THE AMERICAN NATURALIST 



[Vol. L 



tion as a product or derivative of the cytoplasm. I have 

 myself advocated a view diametrically opposite to this, 

 and have urged that the chromatin-substance is to be re- 

 garded as the primitive constituent of the earliest forms 

 of living organisms, the cytoplasmic substance being a 

 later structural complication. On this theory the earliest 

 form of living organism was something very minute, 

 probably such as would be termed at the present day 

 " ultra-microscopic.' ' After I had urged this view in the 

 discussion on the origin of life at the Dundee Meeting of 

 the British Association in 1912 a poem appeared in 

 Punch, 16 dividing biologists into "cytoplasmists" and 

 "chromatinists." I must confess myself still a whole- 

 hearted chromatinist. But before I consider this point 

 I may refer briefly to some other speculations that have 

 been put forward with regard to the nature of the earliest 

 form of life. It is manifestly quite impossible that I 

 should undertake here to review exhaustively all the 

 theories and speculations with regard to the origin of life 

 and the first stages in its evolution that have been put 

 forward at different times. I propose to limit myself to 

 the criticism of certain theories of modern times which, 

 recognizing the fundamental antithesis between chroma- 

 tin and cytoplasm, regard these two cell-constituents as 

 representing types of organisms primitively distinct, and 

 suggest the hypothesis that true cells have arisen in the 

 beginning as a process of symbiosis between them. 

 Boveri, whose merits as a cytologist need no proclama- 

 tion by me, was the first I believe to put forward such a 

 notion ; he enunciated the view that the chromosomes were 

 primitively independent elementary organisms which 

 live symbiotically with protoplasm, and that the organism 

 known as the cell arose from a symbiosis between two 

 kinds of simple organisms, "Monera." 16 



A similar idea lies at the base of the remarkable and 



is Vol. CXLIII, p. 245. 



is Fide Vejdovsky, I. c. I have not had access to the work of Boveri in 

 which he is stated to have put forward these ideas. 



