THE PLACE OF BIOLOGY. 47 



the experimental biologist, and not those of either 

 Descartes the mechanist or Stahl the vitalist, that 

 biology will continue to progress. 



When we examine biological knowledge we find that, 

 however evident in the gross may be the organic determi- 

 nation manifested in the structure and activities of an 

 organism, this determination does not extend to all the 

 observable details. Whether we observe with the naked 

 eye or with the microscope, we find things, so to speak, 

 in lumps or masses of liquid or gas within which we can 

 perceive no organic determination. We also distinguish 

 in a compound organism the constituent cells, each with 

 a more or less independent life of its own, apart from the 

 common life ; and, finally, we have the molecules, 

 each with an apparent existence on its own account. 

 As we pass from the organism outwards into the environ- 

 ment the organic determination seems to fade away 

 altogether. 



It is clear, therefore, that the idea of organic deter- 

 mination leaves unexplained a great mass of what we 

 actually perceive in connection with life. It only enables 

 us to interpret, or mentally grasp in such a way that we 

 can predict, part of the phenomena, the part so inter- 

 preted being what we recognise as specifically biological. 

 To fill up gaps, we cannot avoid making use of physical 

 and chemical interpretations. Imperfect though these 

 interpretations may be, they are the best we can arrive 

 at for the time. 



This may be regarded as a defect in the biological 

 working hypothesis ; but what I now wish to point out 

 and very strongly emphasise, is that this defect is common 

 to every hypothesis of whatever kind. We apply our 



