578 THE HISTORY OF BIOLOGY 



In zoology the experimental method has made slow but sure progress. 

 Strictly speaking, its development has gone hand in hand with the new con- 

 ception of the fundamental problems of biology that has gradually usurped 

 the place of the old phylogenetical idea, dating from the zenith of Darwin- 

 ism. It may be said that the new principle had already been enunciated by 

 Kleinenberg in his above-quoted saying that an organ's form depends upon 

 its function and not upon its origin. Almost at the same time as this utter- 

 ance was made, August Rauber (i84z-i9I7), professor of anatomy at Dorpat, 

 sought to discover the conditions and laws governing the first construc- 

 tion of form in the vertebrate embryo. In opposition to the contemporary 

 belief in the independence of the individual cells he maintains that the whole 

 governs the parts and not vice versa; the egg-cell determines the directions 

 of cleavage by its division of matter, growth is the primary and cleavage 

 the secondary. Division into many cells facilitates the metabolism of sub- 

 stance and renders possible greater strength in the organism and, by special- 

 izing the elements, a far more extensive division of labour, but even when 

 this division of labour is at its maximum, the organism remains a whole, 

 the parts of which are developed under the influence of the whole. Through 

 his efforts to find out in detail the conditions governing the various phases 

 of development, Rauber became, along with His, Goette, and Kleinenberg, 

 a precursor of the later school of evolutional physiology. 



As its founder is named by universal accord Wilhelm Roux (1850-1914). 

 He was born at Jena, where his father was a fencing-master. He studied 

 first under Haeckel and then, at Strassburg, under Goette, and also in Berlin. 

 He became professor, first at Innsbruck, then at Halle, where he worked 

 during the period 1895-19x1. He laboured with never-failing energy and 

 powers of endurance, in speeches and in writing, as a teacher and an agita- 

 tor, on behalf of the method of research and the line of investigation that 

 he originated. As a research -worker he has already been outdistanced by 

 younger minds, but he will always be regarded as a pioneer. However, the 

 same line of thought has been followed from other quarters as well — as, 

 for instance, by the disciples of the above-mentioned plant-physiologists, 

 Sachs and Pfeffer, whose ideas were really in many respects in accord with 

 those of zoological evolutional mechanics. 



Roux was a pupil of both Haeckel and Goette; his works, in fact, bear 

 traces of the influence of both, not only in his early days, but even at a far 

 later age: even into the nineties phylogeny still represented the aim of his 

 research work, and the struggle for existence and selection appear to him 

 the most vital forces of life. But he would achieve this aim, not like Haeckel 

 through a mere comparison between more primitive and more developed 

 forms, but through investigating the mechanical process in ontogenetical ev- 

 olution, such as through the program that Goette had in mind. As a matter 



