118 PLANT PHYSIOLOGY 



Thus to-day we are resigned as regards the question of the origin 

 of life, just as the physicist is as to the origin of matter; and as he 

 pursues his studies on the assumption of the existence of matter, so 

 also we do best when we take for granted the living stuff, and study 

 observationally its nature without speculation upon its first origin. 



The kernel of the doctrine of vitalism, which we have recently 

 regarded as dead and buried, was forced again into recognition by 

 the great Johannes Miiller, after the attempt to reach a purely 

 mechanical conception of life had been wrecked. Truly, we may no 

 longer hold that in the living individual a force reigns which controls 

 everything within. We really see at work within the organism the 

 chemical and physical forces which are active in the inorganic world. 

 But that which within the organism directs the mechanical forces 

 toward a definite goal and unifies harmoniously all that happens 

 within a living individual and leads to a particular purpose (Enhar- 

 mony of the Organism) J cannot be understood from our experience 

 with lifeless nature. 



It has often been attempted to refer the whole life of plants and 

 animals to psychological manifestations. This is, however, an ex- 

 treme view, which fails of profit; while the primitive psychical mani- 

 festations in the life of plants, particularly with reference to the 

 consideration of Fechner, may be allowed some consideration. 



It will be admitted by every far-sighted observer that the purely 

 mechanical conception of life has been set aside, but that, however, 

 there is no reason to take an extreme vitalistic point of view. In 

 order to accentuate the rejection of extreme mechanism in the con- 

 trol of the organism b}>- means of a certainly unprejudiced judgment, 

 I cite the opinion of an eminent physicist and astronomer, which 

 was published at the time when the mechanical view of nature was 

 in vogue, but which has not been properly appreciated. In August, 

 1868, Frederick A. B. Barnard, in his address at the opening of the 

 Chicago meeting of the American Association for the Advancement 

 of Science, spoke the following words. "The vital principle differs 

 from every form of force known to us, and from every other known 

 property or quality, in that it confers upon the body which it ani- 

 mates a special character of individuality, and in that it is incapable 

 of being insulated or of being transferred from body to body. We 

 know it only through the peculiar organizing power which belongs 

 to it, and which is manifested not merely in the chemical changes 

 which it determines, but in the external forms which the resulting 

 compounds assume." 



The manifestation of mechanical forces in addition to that of 



1 Wiesner, Biologic, Zweite Auflage, Wien, 1902. 



2 Presidential Address, seventeenth meeting of the American Association for 

 the Advancement of Science. Translated into the German by Kloden, Berlin, 

 Weidemann'sche Buchhandlung, 1869. 



