270 VARIOUS SPECIES OF MOSQUI1OS. 



He desired us to look at his legs, " that we might be able to 

 tell one day, beyond sea (nor alia), what the poor monks 

 suffer in the forests of Cassiquiare." Every sting leaving a 

 small darkish brown point, his legs were so speckled that it 

 was difficult to recognize the whiteness of his skin through 

 the spots of coagulated blood. If the insects of the genus 

 Simulium abound in the Cassiquiare, which has white waters, 

 the culices or zancudos are so much the more rare; you 

 scarcely find any there ; while on the rivers of black waters, 

 in the Atabapo and the Eio, there are generally some zan 

 cudos and no mosquitos. 



I have just shown, from my own observations, how much 

 the geographical distribution of venomous insects varies in 

 this labyrinth of rivers with white and black waters. It 

 T vere to be wished that a learned entomologist could study 

 en the spot the specific differences of these noxious insects,* 

 which in the torrid zone, in spite of their minute size, act 

 an important point in the economy of nature. What ap- 

 peared to us veiy remarkable, and is a fact known to all the 

 missionaries, is, that the different species do not associate 

 together, and that at different hours of the day you are 

 stung by distinct species. Every time that the scene changes, 

 and, to use the simple expression of the missionaries, other 

 insects 'mount guard,' you have a few minutes, often a 

 quarter of an hour, of repose. The insects that disappear 

 have not their places instantly supplied by their successors. 

 From half-past-six in the morning till five in the afternoon, 

 the air is filled with mosquitos ; which have not, as some 

 travellers have stated, the form of our gnats,t but that 

 of a small fly. They are simuliums of the family Nemo- 

 cera of the system of Latreille. Their sting is as painful 

 as that of the genus Stomox. It leaves a little reddish 

 brown spot, which is extravased and coagulated blood, where 

 their proboscis has pierced the skin. An hour before sunset 



* The mosquito bovo or tenbiguai ; the melero, which always settles 

 upon the eyes ; the tempranero, or putchiki; the jejen; the gnat rivau . 

 the great zancudo, or malchaki , the cqfafi, &c. 



f Culex pipiens. This difference between mosquito (little fly, sinmlium) 

 and zancudo (gnat, culex) exists in all the Spanish colonies. The word 

 zancudo signifies 'longlegs/ qui tiene las zancas largos. The mosquitos 

 of the Orinoco are the mowtiqnes ; the zancudos are the ntarinyouint of 

 French travellers. 



