I] CHEMICAL EMBRYOLOGY 23 



especially, defended Driesch from the charge of interfering with the 

 fundamental necessities of scientific thought. Jennings, however, 

 was able to publish in reply letters from Driesch in which these 

 implications of his position were fully admitted. "Two systems abso- 

 lutely identical in every physico-chemical respect may behave differ- 

 ently under absolutely identical conditions if the systems are living 

 systems. For the specificity of a certain entelechy is among the 

 complete characteristics of a living organism and about this entelechy 

 knowledge of physico-chemical things and relations teaches abso- 

 lutely nothing." Such a basis for experimental work was generally 

 felt to carry with it its own condemnation. 



It is interesting to recall, in this connection, the vivid account 



given by Claude Bernard of the polemic he had with Gerdy at 



the Philomathic Society in Paris, for the Driesch-Lovejoy-Jennings 



controversy simply repeated on a larger scale the arguments 



of the two Parisian biologists sixty years before. "In 1859," 



says Claude Bernard, "I made a report to the Philomathic 



Society in which I discussed the experiments of Brodie and 



Magendie on ligature of the bile-duct, and I showed that the divergent 



results which the two experimentalists reached depended on the fact 



that one operated only on dogs and tied only the bile-duct, while 



the other operated only on cats, and, without suspecting it, included 



in his ligature both the bile-duct and a pancreatic duct. Thus I 



explained the difference in the results they reached and concluded 



that in physiology as everywhere else experiments are rigorous and 



give identical results wherever we operate in exactly similar Conditions. 



A propos of this a member of the Society took the floor to attack my 



conclusions ; it was Gerdy, a surgeon at the Charite, professor in the 



faculty of medicine and known through various works in surgery 



and physiology. 'Your anatomical explanation of these experiments', 



said he, 'is correct, but I cannot accept your general conclusions. 



You say, in fact, that the results of experiments in physiology are 



identical; I deny it. Your conclusion would be correct for inert 



nature but cannot be true for living nature. Whenever life enters 



into phenomena', he went on, 'conditions may be as similar as we 



please, the results may still be different.' To support his opinion Gerdy 



cited cases of individuals with the same disease, to whom he had 



given the same drugs with different results. He also recalled cases 



of like operations for the same disease, but followed by cure in one 



