6 THE LIFE OF THE PLANT 



the development of science and partly with botanists 

 themselves. The historical development of every science 

 requires that the more complicated be preceded by the 

 more elementary, and it is' obvious that the problems 

 of physiology are much more complicated than those of 

 morphology, and presuppose a greater store of informa- 

 tion. The description of organic forms does not necessi- 

 tate any preliminary knowledge. In order to explain 

 the phenomena of life, on the other hand, i.e. to resolve 

 them into the simplest physical and chemical phenomena 

 — which is, as a matter of fact, the object of physiology — 

 it is necessary to start with some knowledge of these 

 phenomena. A morphologist need be but a morpho- 

 logist, whereas a physiologist must to a certain extent 

 be at once a physicist, a chemist, and a morphologist. 

 It was in fact inevitable that the physiological tendency 

 should develop later in the history of science, i.e. only 

 after physics and chemistry had reached a certain point 

 of development. That the backwardness of physiology 

 as a science was nevertheless due in large measure to 

 the onesidedness of botanists themselves is proved by 

 the fact that while the latter were still engaged ex- 

 clusively in the study of form, chemists and physicists 

 were penetrating into the attractive province of the life of 

 the plant and founding the science of plant physiology. 

 The fundamental principles of physiology were therefore 

 formulated by chemists and physicists and not by 

 botanists. The backwardness of botanists in this 

 direction is even more striking when we compare what 

 has been done in the sphere of the physiology of plants 

 with that which has been done in animal physiology. 

 This may seem somewhat paradoxical : the problem of 

 the physiology of plants is far simpler than that of the 

 physiology of animals. The life of plants is far less- 

 complicated than the life of animals, and yet our know- 

 ledge of the latter is much fuller and more definite. 

 However, there are perhaps some extenuating circum- 



