THE ORGANIC AND THE INORGANIC 305 



that we can only so describe it in such a way that it is 

 represented by negative quaHties : we are compelled 

 to postulate its existence in order to avoid philosophical 

 confusion. The universe is therefore a continuum, and 

 an atom or any other body exists wherever it can act. 

 The atoms of a fixed star, so far away that we can only 

 represent its distance in billions of miles, are neverthe- 

 less on our earth as well as at the point of space which 

 we regard as their astronomical position, for the light 

 emitted by them acts on our retinas. The universe is 

 an unitary thing in that it is a continuous medium or 

 substance in the philosophic sense, but it is also a 

 multiplicity in that singularities or conditions of this 

 medium pervade each other throughout space. Such 

 seem to be the conclusions towards which the later 

 physics forces us, and it is interesting to reflect how 

 different biological speculation might have been had it 

 been formulated now instead of half a century ago ! 



Why has a process of evolution occurred at all ? 

 Why is it that tendencies that might have co-existed, 

 that indeed do co-exist to some extent, have become 

 separate from each other ? It is possible to conceive 

 of an organism which contains chlorophyll, and which 

 might therefore S3mthesise carbohydrate and proteid 

 from inorganic substances, but which might also contain 

 a sensori-motor system, and which might therefore 

 expend the energy so obtained in regulated movements. 

 To a certain extent such organisms combining the plant 

 and animal modes of metabolism do exist among the 

 Protista. Yet, the effect of the evolutionary process 

 has been more and more to dissociate the plant and 

 animal modes of metabolism until the typical animal 

 is quite unable to make use of carbon dioxide and 

 water as materials to be synthesised, while the typical 

 plant has lost all power of motion except the tropistic 



