ON THE VITALISTIC VIEW OF NATURE. 373 



ination, insomuch as the different behaviour of different 

 parts of the cellular body towards organic staining 

 solutions reveals to the observer differences of structure 

 otherwise indistinguishable. Yet Professor Pfeffer, 1 who 

 has studied the absorbing powers of cellular substances 

 with much care, states that these cannot in the least 

 be foretold, but can only be determined empirically ; 

 nor is the fact that cells require some substances 

 for their life, while others are harmful, sufficient to 

 enable us to predict that either will be absorbed or 

 rejected. Again, hybridisation has been much studied 

 by gardeners and breeders, and also, since the time 

 of Darwin, by naturalists ; nevertheless, the result of 

 cross-fertilisation of individuals belonging " to different 

 families or species, or even only to different varieties," 

 cannot be theoretically foretold, but " can only be dis- 

 covered by means of experiment." 2 



This ignorance in which we are still placed as to the 

 forms as well as functions of living matter, has been a 

 subject of much comment by biologists all through the 



1 See W. Pfeffer, ' Ueber Auf- 

 nahme von Anilinfarben in lebende 

 Zellen.' Untersuchungen aus dem 

 botanischen Institut zu Tiibingen. 

 Quoted by Hertwig, ' The Cell,' p. 

 136. 



2 Hertwig, 'The Cell,' p. 310. 

 Another point, strongly urged by 

 Claude Bernard, is, that a knowledge 

 of structure in living beings i.e., 

 anatomical knowledge in no wise 

 suffices to explain the functions, does 

 not lead to physiological knowledge. 

 See ' La Science Expe"ri men tale,' p. 

 105, " L'impuissance de 1'anatomie a 

 nous apprendre les fonctions organ- 

 iques devient surtout eVidente dans 

 les cas particuliers ou elle est 



re"duite a elle - meme. Pour les 

 organes sur les usages desquels 

 la physiologic expeYitneutale n'a 

 encore rien dit, 1'anatomie reste 

 absolumeut inuette. C'est ce qui 

 a lieu par exemple pour la rate, 

 les capsules surre'nales, le corps 

 thyro'ide, &c., tous organes dont 

 nous connaissons parfaitement la 

 texture anatomique, mais dont 

 nous ignorons completement les 

 fouctions. De meme, quand sur 

 un animal on de"couvre un tissu 

 nouveau et sans analogue dans 

 d'autres organisines, 1'anatomie est 

 incapable d'en ddvoiler les pro- 

 prie'te's vitales." 



