78 EXPERIMENTAL RESEARCHES 



example, that a microbe had penetrated into a 

 cell, but had not the power of directly splitting 

 off the fatty bodies ; then these substances 

 would not be immediately assimilable by it. 

 Yet the microbe might obtain possession of 

 them if it secreted a poison injurious to the cell, 

 which would decompose the protoplasm. In 

 such a case the fat would be liberated, and 

 could be assimilated by the micro-organism, 

 even though the immediate affinity between 

 the two were very low. At any rate, these 

 considerations may so far be of interest as 

 they touch upon an issue of biology and patho- 

 logy, which has, on the whole, been somewhat 

 pushed into the background of late years, since 

 one has accustomed oneself in every infective 

 process to think in the first place of a specific 

 bactericidal action through the direct toxic 

 substances of the body, its haptines, etc. This 

 has led to our neglecting somewhat the simple 

 possibility that certain micro-organisms may 

 only be able to grow if certain conditions are 

 given for their development, and that they must 

 perish if these conditions are withheld. To 

 my mind this possibility is of importance in 

 many respects, and is especially significant for 

 our views on cancer immunity. At any rate, 



