308 MAGNALIA NATURE: OR THE GREATER 



both those that in the hierarchy of knowledge are set above 

 and below, and those that rank alongside of our own. 



Before the great problems of which I have spoken, the 

 cleft between zoology and botany fades away, for the same 

 problems are common to the twin sciences. When the 

 zoologist becomes a student not of the dead but of the living, 

 of the vital processes of the cell rather than of the dry bones 

 of the body, he becomes once more a physiologist, and the 

 gulf between these two disciplines disappears. When he 

 becomes a physiologist, he becomes ipso facto a student of 

 chemistry and of physics. Even mathematics has been 

 pressed into the service of the biologist, and the calculus of 

 probabilities is not the only branch of mathematics to which 

 he may usefully appeal. 



The physiologist has long had as his distinguishing charac- 

 teristic, giving his craft a rank superior to the sister branch 

 of morphology, the fact that in his great field of work, and 

 in all the routine of his experimental research, the methods 

 of the physicist and the chemist, the lessons of the anatomist, 

 and the experience of the physician, are inextricably blended 

 in one common central field of investigation and thought. 

 But it is much more recently that the morphologist and 

 embryologist have made use of the method of experiment, 

 and of the aid of the physical and chemical sciences, even 

 of the teachings of philosophy : all in order to probe into 

 properties of the living organism that men were wont to take 

 for granted, or to regard as beyond their reach, under a 

 narrower interpretation of the business of the biologist. 

 Driesch and Loeb and Roux are three among many men, 

 who have become eminent in this way in recent years, and 

 their work we may take as typical of methods and aims such 

 as those of which I speak. Driesch, both by careful experi- 

 ment and by philosophic insight, Loeb by his conception of 

 the dynamics of the cell and by his marvellous demonstra- 

 tions of chemical and mechanical fertilisation, Roux with 



