84 BIOLOGY AND PHYSICAL SCIENCES 



during life are only phases of the organic 

 determination which is the key to all the 

 phenomena of life. They must be looked at 

 from the physiological or biological standpoint, 

 and not merely from that of the physical 

 sciences. The details of bodily structure must 

 likewise be interpreted as the expression of 

 organic determination. 



Now it seems to me that the actual pro 

 gress of physiology, and of biology generally, 

 corresponds exactly with the increasing 

 realisation of this aim. It has already been 

 shown that in tracing the history of phy 

 siology we find that on the whole there 

 has been no apparent progress whatsoever 

 towards the mechanistic goal. On the 

 other hand it is perfectly plain that there has 

 been enormous progress, not merely in ascer 

 taining isolated facts, but in tracing organic 

 determination in every detail of bodily struc 

 ture and physiological activity. 



To illustrate this conclusion in detail it 

 would be necessary to present to you, not 

 a single lecture, but a whole text-book of 

 physiology. I shall, however, try to give 

 a single illustration by tracing roughly part of 



