24 presidp:nt's addrp:ss. 



proteins and fats have not yt^t been examined in the same way. 

 May we not hope that these studies may be ext(ended in con- 

 nection wdth fermentative activity? 



The functions of living matter have been the object of that 

 branch of science in which I have been a student. The aim of 

 the physiologist, is to explain the behaviour of living things in 

 terms of the mechanical, physical, chemical, and psychical sciences. 

 It is believed that progress is at present possible if an endeavour 

 is made to reduce biological phenomena to physical and chemical 

 problems. Living things are built from inanimate matter, and 

 the attributes of living things are the expressions of the pro- 

 perties of matter. I am aware that such a belief is condemned 

 as materialistic. I must confess, however, that I see no diffi- 

 culty in supposing that, as heat, light, magnetism, and electricity 

 are qualities of the arrangement of matter, the psychical qualities 

 of the higher forms of living things are likewise material. 

 Heat apart from matter does not exist. Why should we suppose 

 that memory and thought exist apart from some matter in the 

 living organism ? Whoever will become acquainted witli the 

 history of physiological knowledge will find that progress is 

 represented by the explanation of a greater number of the func- 

 tions of animals and plants in terms derived from the study of 

 physics and chemistry. On such a conception, there is no sucli 

 thing as inanimate matter, though there may be lifeless objects. 



With these ideas in your mind, I invite your attention to the 

 problem of variation as exemplified in the different functions of 

 each kind of animal and plant. For many centuries, naturalists 

 had believed that each kind of animal or plant was endowed 

 with unchanging characters. The fixity of species was con- 

 sidered axiomatic by zoologists and botanists. Darwin and his 

 followers have demonstrated to us the progressive evolution 

 from one form to another in animal and plant. Every animal 

 and plant showed a certain degree of variation in its characters. 

 Some of these characters favoured the living organism in its 

 struggle for existence, others rendered it less able to cope with 

 the conditions of environment. Some organisms survived longer 

 and had a better chance of reproducing their kind, others died 



