GENETICS 181 



conditions of cultivation this relation turns anti-biotic and 

 pathological, this, I submit, indicates that a loss of symbiotics 

 and of general vitality and resisting power go together. 



"Lastly, it may be recalled," says Prof. Bateson, "that 

 in sterility we are almost certainly considering a meristic 

 phenomenon. Failure to divide is, we may feel fairly certain, 

 the immediate 'cause' of the sterility." 



But failure to " divide " is failure in producing an 

 adequate symbiotic elan due to failure of bio-chemical stimula- 

 tion, and this, in turn, is due to a distortion of biological 

 symbiosis. There is an insufficiency of symbiotic momentum. 



Prof. Bateson thinks we are justified in presuming that 

 there are factors which can arrest or prevent cell-division. 

 Precisely. There are. Many factors, as we have seen, must 

 co-operate to produce adequate stimulation of so complex a 

 mechanism as that involved in the fertilisation of highly 

 symbiotic organisms. The weakening of any one of these 

 factors must certainly seriously interfere with proper cell- 

 division, just as it would also interfere with, let us say, the 

 proper functioning of the corpus luteum or its equivalent in 

 the lower orders. 



The same causes that produce the manifold phenomena of 

 nemesis of reproduction and stimulate vegetative growth at 

 the expense of sexual development, must also in the long run 

 produce disturbances of cell-division, which may become pro- 

 nounced at any moment and inhibit further division. 



Prof. Bateson endorses the statement of Samuel Butler: 

 " To me it appears that the ' origin of variation,' whatever it 

 is, is the only true ' origin of species,' " which I also fully 

 endorse, although I do not share Prof. Bateson's belief that the 

 origin of variation is so very mysterious. 



In his address at Melbourne as President of the British 

 Association, Prof. Bateson made the statement that we cannot 

 even imagine any changes in progress around us in the con- 

 temporary world likely to culminate in the evolution of forms 

 distinct in the larger sense (species as distinct from variations). 



