I.— PHYSIOLOGY. 175 



might expect to find such elementary forms of life coexisting with it did 

 we but know how to look for them. The filterable viruses may represent 

 such forms, and their chemical characters may resemble those that we 

 find in the nucleus of the cell. The ability to synthesise protein may be 

 a property which living material only acquired at a late stage of its evolu- 

 tion, and that property may be one which in the process of time has come 

 to be essential for the maintenance of the complex structure of the nucleus 

 as we see it to-day. 



I have dwelt for a time on these problems of synthesis in relation to the 

 structure of the cell because, however speculative they appear to be in the 

 present state of knowledge, it seems to me that it is necessary to get some 

 picture of them. Progress in synthetic chemistry has been intimately 

 associated with the ability to represent objectively the structure of sub- 

 stances and the changes which take place when they are undergoing 

 reaction. We know much about the manifold chemical activities of the 

 cell, but, until we can by deductive methods get some picture of its organi- 

 sation, the problems which I have attempted to sketch briefly in this 

 address will not be solved. 



The view has sometimes been expressed that it is the task of physiology 

 to study the reactions of the whole animal because the whole animal is the 

 unit. That is perfectly true if our object be only to describe and account 

 for animal behaviour. But there is just as truly a cellular physiology in 

 which the cell is the unit. Until we can analyse and understand the 

 beha\aour of the cell we cannot expect fully to explain the reactions of 

 the whole animal. 



In stressing therefore the importance of studying the activities of the 

 cell as such for the progress of our science, I feel that I am not at variance 

 with some of my predecessors in this office. Like them, I have attempted 

 to indicate the lines upon which progress may come in our endeavour to 

 elucidate some of the problems to which I have referred. 



Classical organic chemistry with all its achievements of synthesis 

 cannot yet claim to rival the synthetic activities of the cell. That it will 

 ever do so as regards the synthesis of our main foodstuffs, the proteins, 

 carbohydrates and fats, cannot be foreseen. Both from the chemical and 

 economic points of view the signs at present are not very hopeful. The 

 synthetic breakfast table is a myth and likely to remain one. Man has, 

 so far, not learnt from Nature the mechanisms of syntheses that she 

 uses and on which his existence depends, so that the tilling of the soil and 

 reaping of the harvest must for long remain his most vitally important 

 occupation. 



