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, Cornil 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 that 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 
