MODERN BIOLOGY 313 



an independent branch of study at the universities. All his practical endeav- 

 ours, how^ever, he preferred to base upon a careful study of the functions of 

 the body; for this purpose he started in the year 1796 the journal Archiv fur 

 Physiologic, which under various names and editorial conditions has sun 

 vived up to the present day. In an essay in this journal he expounded a 

 general biological theory that exercised great influence on his own time and 

 is therefore worthy of reference. This essay, "Von der Lebenskrajt ," contains, 

 like many others written in that age of pioneers, a number of ideas fruitful 

 both for the contemporary world and for posterity, side by side with a mass 

 of uncritical and fantastic nonsense. After a philosophical introduction 

 touching the terms "matter," "phenomenon," and "idea," Reil criticizes 

 the vitalistic speculation of preceding ages and declares, with an obvious 

 reference to Stahl, that phenomena in the animal kingdom cannot emanate 

 from an immaterial soul, because assumptions as to supernatural influences 

 explain nothing. Rather, the basis of all phenomena in the animal body that 

 are not ideas must be sought only in corporeal matter and in "the form and 

 composition" in its various constituent parts; to matter's different "compo- 

 sition" in muscles, nerves, and bones are due the different properties and 

 functions of those parts. Reil has here learnt not only from Stahl, but also 

 from the animal chemistry that started in connexion with Lavoisier and had 

 been developed in his own time. Unfortunately, however, he does not by 

 any means come up to the standard already reached by his contemporaries 

 in this respect; thus, he did not realize the relation between the interchange 

 of gas in plants and animals, a fact which Schelling, for instance, during the 

 same period realized well enough to be able to ascribe fundamental impor- 

 tance to it (Part II, p. xyy), and he shares the ancient popular belief that 

 the grain of seed in the earth and the still unbrooded tgg are "dead" and ac- 

 quire life by being provided with warmth and other fine components of life. 

 Herein lies the weakness of Reil's speculation, and, generally speaking, both 

 chemistry and philosophy lead him into somewhat strange paths. Having 

 thus started by defining the idea of force in nature and the relation between 

 phenomena and the properties in matter which produce them, he goes on to 

 explain the life-force in animate creatures as being the relation between 

 more individualized phenomena and a special kind of matter, wherein a 

 differentiation is made between vegetative force in plants, animal force in 

 animals, and reason in man. Growth in inanimate and animate nature is 

 declared to be of an identical character, so that animal growth is at once 

 termed ''tierische Kristallisafion." But besides these fanciful ideas Reil suc- 

 ceeds in producing a definition of the term "organ" itself that undoubtedly 

 represents a real advance. Starting from the elder Darwin's theory of fibre 

 as a basic component in the animal organism (Part II, p. X95), he describes 

 various categories of fibres: cell-tissue fibres, bone-, muscle-, and nerve-fibres. 



