16 MOSQUITOES OF NORTH AMERICA 



above all at Mompox, at Chilloa, and at Tamalameque. It is here that it is the 

 largest and strongest, and here its legs are blacker. One can hardly help laugh- 

 ing when one hears the missionaries dispute about the size and ferocity of the 

 mosquitos on different parts of the same river. In the midst of a country where 

 they are ignorant of what is going on in the rest of the world this is the favorite 

 subject for conversation. ' How sorry I am for you ! ' the missionary of the 

 Eaudales on our departure said to the missionary of the Cassiquiare. ' You are 

 alone just as I am in this country of tigers and of apes ; fishes where I live are 

 rarer than here ; the heat there is greater, but as to the flies, I can boast that with 

 one of mine I can beat three of yours.' 



" This voracity of insects in certain plaoes, this avidity with which they attack 

 man,* this activity of the venom, variable in the same species, are remarkable 

 facts, but they find their analogy with some of the larger animals. The croco- 

 dile of Angostura pursues man, while one can bathe peacefully at Nueva Barce- 

 lona in the Nevari River in the midst of these carnivorous reptiles. The jaguars 

 of Maturin, of Cumanacoa, and of the Isthmus of Panama are cowardly com- 

 pared with those of the upper Orinoco. The indians know very well that the 

 monkeys of such and such a valley are easily domesticated, while others of the 

 same species, caught elsewhere, wall die of hunger rather than submit to slavery. 



" The people in America form ideas concerning the health of climates and 

 concerning pathological phenomena, just as the savants of Europe do, and these 

 ideas, just as with us, are diametrically opposed to one another according to 

 the provinces into which the new continent is divided. On the Eio de la Magda- 

 lena the abundance of mosquitos is regarded as a nuisance, but very healthy. 

 * These animals,' say the inhabitants, ' bleed us slightly, and in an excessively 

 warm country, preserve us from the tabardillo, from scarlet fever, and other in- 

 flammatory maladies.' On the Orinoco, the banks of which are very dangerous 

 to health, the sick people accuse the mosquitos of all the diseases that they have. 

 ' These insects are born in corruption and increase it; they inflame the blood.' 

 It is useless to deny this popular belief which considers mosquitos as acting in 

 a salutary way by local bleeding. Even in Europe the inhabitants of swampy 

 countries do not ignore the fact that insects irritate the dermal system. Far 

 from diminishing the inflammatory condition of the skin, the bites increase it. 



" The abundance of gnats and mosquitos characterizes unhealthy countries 

 only when the development and multiplication of these insects depends upon 

 the same causes which give birth to miasmas. These injurious animals love a 

 fertile soil covered with vegetation, with stagnant pools, and moist air which is 

 never agitated by the -wdnd. They prefer, in place of bare spots, shade, that 

 degree of light, of heat, and of humidity, which all favor the action of chemical 

 affinities and accelerate the putrefaction of organic substances. Do the mos- 

 quitos themselves add to the unheal thiness of the atmosphere? When one 

 thinks that, at an elevation of three or four fathoms, a cubic foot of air is often 

 peopled by a million winged insects and that these have within them a caustic 

 and poisonous liquid — ^M^hen one remembers that several species of Culex are 

 from the head to the end of the body (without counting the legs) 1-4/5 lines 

 long — when one considers finally that in this swarm of gnats and mosquitoes, 

 spread like a cloud in the air, there are a great number of dead insects carried by 

 the force of the ascending current and by the side currents which are caused by 

 the unequal heat of the soil — one asks if the presence of so much animal matter 

 in the air does not give birth to certain miasmas. I think that these substances 



• " How surprising is this voracity, tJiis appetite for blood on the part of little insects which 

 feed normally upon plant juices, which live in an almost uninhabited country ! ' What would 

 these animals eat if we did not go through here,' the Creoles often say in passing places where 

 there are only crocodiles covered with scaly skin and hairy monkeys." 



