THE MICROBES OF HUMAN DISEASES. 187 



Marchiafava and Celli. But experiments undertaken 

 to show that these granules are microbes have as yet 

 afforded no certain results. 



In short, Comil remarks : " Since bacteria are 

 found neither in the internal organs nor in the blood 

 of those who die of intermittent fever, we are tempted 

 to suppose thaji the virulent agent resides in the sur- 

 face of the mucous membrane — for example, in that of 

 the digestive canal ; and that the chemical poisons pro- 

 duced under the influence of these micro-organisms 

 penetrate thence into the blood. They then act on 

 the red corpuscles of the blood." 



Finally, we must remember that many continuous 

 fevers, especially those of hot countries, seem to be 

 complicated by the presence of two parasitic elements, 

 as we have said in describing Nageli's diblastic theory. 

 To the marsh microbe, which comes from the soil, 

 another is added, of which the immediate origin is 

 due either to direct contagion, or to some other telluric 

 or atmospheric local influence. 



VI. Recurrent Fever and Yellow Fever. 



We place these two diseases together, simply 

 because they have rarely been observed in France. 

 Recurrent fever, or relapsing typhus, is a disease 

 which has been observed in Germany, Russia, Ireland, 

 and India, in which latter country it is called jungle 



