6lO THE HISTORY OF BIOLOGY 



connexion to the law of the conservation of energy is a matter for the physi- 

 cists to consider. Driesch having thus already at an early stage taken up a 

 position essentially on the other side of the boundary line between meta- 

 physics and empirical research, he has ultimately adopted this step formally 

 as well; he is now professor of philosophy at Leipzig and in that capacity 

 has been engaged in speculations of the most abstract kind. 



Another vitalist of whom a good deal has been heard is Emanuel Radl. 

 He was born in Bohemia in 1873, studied at Prague, and has been a lecturer 

 in physiology there. His research work has concentrated partly on physio- 

 logical subjects — he has dealt with the tropisms in the lower animals — 

 and partly on the morphology of the brain. He is best known, however, 

 for his Geschichte der biologischen Theorien der Neu^eif, a much read and widely 

 quoted work, the first part of which has come out in two editions, which 

 are essentially different from each other. To examine this work properly, 

 however, we must have some knowledge of its author's biological stand- 

 point, which is clearly apparent in his most important monograph, Neue 

 Lehre vom xentraUn Nervensysfem. In its introduction the author shows that 

 he holds particularly broad views, and, on the other hand, that he is fully 

 convinced of the soundness and future value of his own ideas. The Darwin- 

 istic morphology is rejected as a soulless description and specification of dif- 

 ferent developmental forms one after another; he gives slightly more credit 

 to experimental evolutional physiology on the lines of Roux, but the science 

 that in Radl's view has the greatest future is that of ideal morphology, of 

 which he himself is an exponent. As a pioneer of this science he mentions 

 Geoffroy Saint-Hilaire, and also, though in a less degree, Cuvier; its aim 

 is stated to be to discover the ideas according to which the forms of living 

 organisms are constructed. "Many ideas compete at the root of organic life 

 for precedence, and an ideal structure forms the basis of every organism." 

 This must be sought for by means of comparisons throughout the animal 

 kingdom, for only thus can we gain any knowledge of the fundamental ideas 

 of existence. This is, of course, simply the idealistic morphology of the begin- 

 ning of the nineteenth century over again. When it comes to working out his 

 idea in detail, however, we find only a collection of disjointed sentences taken 

 from other authors, in conjunction with his own, not always very convincing, 

 observations concerning the object of his investigation, the central nervous 

 system. Apathy's fibrilla theory is thus maintained as against the doctrine 

 of neurones; Radl himself describes in word and illustration one category 

 of fibrillar, existing, according to him, throughout the animal kingdom, 

 which are convoluted in a special way at the entrance to every ganglion 

 and which he terms "cascade fibrillar." They do not, however, give the 

 impression of being very natural and would appear rather to have arisen 

 through being cut obliquely or through the ordinary nerve-fibres' being 



