114 Causes and Course of Organic Evolution 



living organism on which the bacteria feed. But the greatly 

 more complex tissues of the former often secrete or set free 

 products that are neutralizing to a greater or less degree to 

 many chemical agents. 



Other substances, however, than those mentioned above, 

 if in sufficient concentration, act similarly on the protoplasm 

 of higher plants and animals as on that of bacteria. Thus 

 Loeb (59: 21) says: "Budgett has observed that in many 

 infusorians visible changes of structure occur in the case of lack 

 of oxygen; as a rule the membrane of the infusorian bursts or 

 breaks at one point, whereby the liquid contents flow out. 

 Hardesty and I found that Paramoecium becomes more 

 strongly vacuolized, when deprived of oxygen, and at last bursts. 

 Amoebce likeT\'ise become vacuolized and burst under these con- 

 ditions. Budgett found that a number of poisons, such as po- 

 tassium cyanide, morphine, quinine, antipyrine, nicotine, and 

 atropine, produce structural changes of the same character 

 as those described for lack of oxygen. As far as KCN is con- 

 cerned, Schoenbein had already observed that it retards the 

 oxidation in the tissues, while Claude Bernard and Geppert 

 confirmed this observation. For the alkaloids, W. S. Young 

 has shown that they are capable of retarding certain processes 

 of autoxidation. This accounts for the fact that the above- 

 mentioned poisons produce changes similar to those observed 

 in the case of lack of oxygen." 



The action throughout in higher animals is apparently one 

 in which the vegetative cells — those of the alimentary canal 

 and of the unstriped muscle, of the associated glands of the 

 canal, of the blood corpuscles, of the heart and the lungs — 

 become disturbed and in time death ensues, through disruption 

 of the energized molecules that compose the living substance 

 of them. Several suggested explanations might be given; but 

 we here propose that such chemical bodies may have a special 

 affinity for some such constituent of the protoplasmic molecule 

 as oxygen, and by union of these a breaking up of the proto- 

 plasmic molecule ensues, thereby stopping or setting free the 

 rhythmic flow of the biotic energy. 



