PROBLEMS OF BIOLOGY 315 



and the mathematician being able to explain the form of the 

 one, by simple laws of spatial arrangement where molecule 

 fits into molecule, seems to deter, rather than to attract, the 

 biologist from attempting to explain organic forms by mathe- 

 matical or physical law. Just as the embryologist used to 

 explain everything by heredity, so the morphologist is still 

 inclined to say ' the thing is alive, its form is an attribute 

 of itself, and the physical forces do not apply.' If he does 

 not go so far as this, he is still apt to take it for granted that 

 the physical forces can only to a small and even insignificant 

 extent blend with the intrinsic organic forces in producing 

 the resultant form. Herein lies our question in a nutshell. 

 Has the morphologist yet sufficiently studied the forms, 

 external and internal, of organisms, in the light of the pro- 

 perties of matter, of the energies that are associated with it, 

 and of the forces by which the actions of these energies may 

 be interpreted and described ? Has the biologist, in short, 

 fully recognised that there is a borderland not only between 

 physiology and physics, but between morphology and physics, 

 and that the physicist may, and must, be his guide and teacher 

 in many matters regarding organic form ? 



Now this is by no means a new subject, for such men as 

 Berthold and Errera, Rhumbler and Dreyer, Biitschli and 

 Verworn, Driesch and Roux, have already dealt or deal with 

 it. But on the whole, it seems to me that the subject has 

 attracted too little attention, and that it is well worth our 

 while to think of it to-day. 



The first point then, that I wish to make in this connec- 

 tion is, that the Form of any portion of matter, whether it 

 be living or dead, its form and the changes of form that are 

 apparent in its movements and in its growth, may in all 

 cases alike be described as due to the action of Force. In 

 short, the form of an object is a ' diagram of Forces,' in this 

 sense, at least, that from it we can judge of or deduce the 



