THE RELATION OF MOSQUITOES, FLIES, TICKS, FLEAS, 
AND OTHER ARTHROPODS TO PATHOLOGY. 
By G. MAROTEL. 
It is a matter of common knowledge to-day that while there are 
many arthropods which live a free life, there are also many others 
which are parasites, causing in man and also especially in the do- 
mestic animals many and varied diseases, the origin and nature of 
some of which have been known for a long time. It would be banal 
to recall that phthiriasis is caused by lice, and that certain larve of 
Diptera, such as the cestrids, may occasion the disease called myasis. 
This old pathogenic role, which has been taught to all the medical 
and veterinary generations of our time, is quite true. But it is not 
of this that I wish to speak. It is of a new role, brought to light only 
within the last ten years, the importance of which now grows greater 
every day, for scarcely a month passes, I might almost say not a week, 
that some work does not appear which adds some unknown fact or 
new theory relative to it. 
It has to do with one of the questions which in the whole range of 
parasitic pathology can, with the greatest right, claim to be of prac- 
tical importance. The danger from the arthropods is a direct con- 
sequence of their habits. It only exists in connection with those 
whose habits are to seek association with men and domestic animals, 
to bite them and to suck their blood. 
Everyone knows that a number of species, such as mosquitoes 
and gadflies, pass a considerable part of their time in flying from one 
victim to another, in the same manner that bees wander from flower 
to flower. Let us suppose, then, that in the course of these wander- 
ings one of them happens to fasten itself on an individual affected by 
a parasitic or bacterial disease, the agent of which lives in the blood. 
In sucking the blood it absorbs also the germs which are contained in 
it, and thus is infected. Should it then attack a healthy person there 
is danger that it will inoculate him with the disease. This is why 
@Translated by permission from Annales de la Société d’Agriculture, Sciences 
et Industrie de Lyon, 1906, pp. 279-802. 
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