6o6 THE HISTORY OF BIOLOGY 



question is ascribed to a cause that is stated to possess a general significance 

 for all vital phenomena, but when shortly afterwards it is declared that the 

 worker-ants do not exhibit any such tropism, no attempt is made to explain 

 this notable exception. And the same lack of consecutive thought is dis- 

 played everywhere. The development of the egg is explained as being due 

 to oxidization; that this development can be caused by such diverse external 

 influences as, on the one hand, a solution of acid and, on the other, the 

 prick of a needle certainly evokes some surprise, but no more than that the 

 whole phenomenon is after all accounted for as being a physico-chemical 

 process, it not being considered at all necessary to discuss the most remark- 

 able feature of all — namely, the nature of the egg itself. Indeed, in the 

 opinion of Loeb, there exist no structural conditions whatever; there is 

 hardly any question of the organism's possessing a chemical composition 

 of its own; all that takes place in the organism is the result of outside im- 

 pulses, the result being that no discrimination whatever is made between 

 one life-phenomenon and another, whether it is a question of sea-urchins, 

 insects, or frogs. The goal to be attained is, as we have said, a mechanical 

 explanation of life, but just because of this exclusive interest for external 

 influences the explanation proves to be essentially negative — a denial of 

 the existence of any operating forces other than the said external influences. 

 When he comes to discuss more complicated problems, Loeb shows the most 

 amazing lack of criticism; he gives an account of Mendelism and declares 

 that the riddle of heredity is thereby solved, but a little further on he as- 

 serts the exact opposite, that any ossean can be crossed with any other os- 

 ean;^ he himself has kept such hybrids alive for a month. The explanation 

 of what has taken place is manifestly a parthenogenetical development of 

 the eggs through the "activating" influence of foreign sperm; but Loeb 

 literally declares that it is possible to obtain a hybrid between a salmon and 

 a flounder. With such facility in drawing conclusions and such irresponsi- 

 bility as to their consequences there need be no limit to one's flights of 

 imagination, and, moreover, one is free in the long run to dispense with 

 all exchanges of views with scientists possessing a normal sense of respon- 

 sibility. Loeb is without doubt a brilliant experimentalist, and as such he 

 deserves mention among the pioneers, though among biological thinkers he 

 can claim no place. 



Vitalistic explanations of life 

 On the whole, the mechanistic speculations in the sphere of modern biology 

 give a somewhat monotonous impression and it is therefore hardly worth 

 while making the acquaintance of any more representatives of this line of 

 thought. Those who are constantly making the assertion that there is no 



1 See The Mechanistic Conception of Life, p. 2.4: "It is possible to cross practically any marine 

 teleost with any other." 



