THE ORGANISM 59 



And there is the most striking phenomenon of 

 all — artificial parthenogenesis. It was the monu- 

 mental achievement of Jacques Loeb that the eggs 

 of certain life-forms which normally develop only 

 with the aid of a spermatozoon were caused to de- 

 velop by physicochemical means. Also, other un- 

 fertilized eggs have been caused to develop by means 

 of rays — ultra-violet rays in Jacques Loeb's experi- 

 ments, radium rays in G. Bohn's experiments. 



It is a noteworthy fact that observations made on 

 organisms have led directly to important discoveries 

 or advances in physical science. According to Wil- 

 helm Ostwald, H. J. van't Hoff was led to his con- 

 clusions concerning solutions through a conversation 

 with his colleague, the botanist De Vries. The 

 twitching of the muscles of the leg of a frog (ob- 

 served by Galvani), as Jacques Loeb says, "a mis- 

 understood biological observation, became the germ 

 for the development of electrochemistry." Helmholtz 

 formulated his law of the conservation of energy 

 following his researches into phenomena of heat of 

 the animal body. 



