2 THE BODY AT WORK 



used somewhat loosely to designate any piece of the animal 

 mechanism which has a distinct function to perform. The 

 physiologist studies the results of the activity of an organ. 

 He watches it in action, and endeavours to explain the process 

 by which it produces its effects. Then follows the anatomist, 

 who, taking it to pieces, examines it with the utmost thorough- 

 ness which scalpel and forceps or microscope allows, with a 

 view to ascertaining whether its structure will support the 

 physiologist's hypothesis as to its mode of action. This in 

 the vast majority of cases has been the history of scientific pro- 

 gress. The physiologist has preceded the anatomist in drawing 

 inferences as to the manner in which things are done. The 

 anatomist, after a further examination of structure, has 

 either admitted the plausibility of his explanation, or has 

 interposed the objection that the part was incapable of 

 working in the way supposed. 



This comparison of anatomy and physiology must not be 

 pushed too far. Enough has been said to emphasize the distinc- 

 tion between them. The one treats of form, the other of func- 

 tion. The one looks at structure, the other at action. Anatomy 

 in its limited and logical sense has nothing to do with the uses of 

 a part ; its business is to measure it. Physiology has nothing to 

 do with the measurements of parts ; its duty is to watch for 

 movement. Every living thing may be contemplated either 

 in its statical or in its dynamical aspect. Physiology looks at 

 it from the latter point of view. 



Surveying his province, the physiologist asks himself : 

 " Who are my subjects ? What am I to find out about them ? 

 What methods, in addition to direct observation, may I use to 

 obtain this information ?" His oversight embraces all living 

 things. It is no longer reasonable to make a distinction 

 between human and animal physiology, or between the 

 physiology of animals and the physiology of plants. No 

 human being can take all science for his field. If he contents 

 himself with scratching its surface, he will assuredly raise but a 

 meagre crop, and that mostly weeds. But he is far behind the 

 spirit of his age if he declines to sow in his own little patch seeds 

 of thought which have blossomed in other localities, however 

 remote. The man whose purpose in studying physiology is 

 to obtain a knowledge of the working of the healthy human 



