62 DIRECT INJURIES CAUSED BY INSECTS. 
From Humboldt also we learn that “between the little harbour of 
Higuerote and the mouth of the Rio Unare the wretched inhabitants are 
accustomed to stretch themselves on the ground, and pass the night buried 
in the sand three or four inches deep, leaving out the head only, which they 
cover with a handkerchief.” This illustrious traveller has given an ac- 
count in detail of these insect plagues, by which it appears that amongst 
them there are diurnal, crepuscular, and nocturnal species, or genera: the 
Mosquitos ov Simulia flying in the day; the Zemporaneros, probably a kind 
of Culex, flying during twilight ; and the Zancudos or Culices in the night. 
So that there is no rest for the inhabitants from their torment day or night, 
except for a short interval between the retreat of one species and the attack 
of another. We learn from this author that the sting or bite of the 
Simulium is as bad as that of the Stomowys before noticed. 
The Rhagio Columbaschensis of Fabricius, a native of Banat and the 
adjacent parts of the banks of the Danube, is a species of Simulium, and 
one of the most obnoxious of all the insects which attack man and do- 
mestic animals. (See KGllar’s work on Obnoxious Insects ; a translation 
of part of which, by the Misses Loudon, has recently been published. 
The work of Pohl and Kéllar on the obnoxious insects of Brazil also 
contains many notices of their attacks upon man.) 
It is not therefore incredible that Sapor, king of Persia, as is related, 
should have been compelled to raise the siege of Nisibis by a plague of 
gnats, which, attacking his elephants and beasts of burthen, so caused the 
rout of his army, whatever we may think of the miracle to which it was 
attributed; nor that the inhabitants of various cities, as Mouffet has col- 
lected from different authors*, should, by an extraordinary multiplication 
of this plague, have been compelled to desert them; or that by their 
power to do mischief, like other conquerors who have been the torment of 
the human race, they should have attained to fame, and have given their 
name to bays, towns, and even to considerable territories.* 
served, speaking of his residence at the Havana, “The disagreeables are ants, 
scorpions, mygales, and mosquitos. The latter were quite a pest on my first 
arrival within the tropics ; but now I mind them about as much as I did gnats in 
England.” 
1 Humboldt’s Personal Narrative, ©. T. v. 87. Most writers by the term mos- 
quitos mean gnats; and for them it is chiefly employed, but may be regarded as 
including both plagues. 
2 Theodorit. Hist, Becl. 1. ii. ¢, 30. 
5 Mouffet, 85. Amoreux, 119. , 
4 Viz. Mosquito Bay in St.Christopher’s; Mosquitos, a town in the Island of 
Cuba; and the Mosquito country in North America. ‘Though in many cases it may 
be impossible to prevent the attacks of gnats, it is certain that a little care would 
often secure the inmates of houses, distant from stagnant waters, from these pests, 
for which they have solely to thank their open water-tubs or cisterns in their gar- 
dens, in which they are constantly breeding. Dr, Franklin, whose admirable habit 
of minute observation embraced all subjects, long since pointed this out, and I myself 
found that the gnats which’so annoyed us in the house we occupied at Pisa late in the 
autumn of 1830, as to require gauze mosquito curtains to all the beds, though it was 
far distant from the river or any pond, all proceeded from an open ornamental stone 
cistern in the garden, constantly left half full of water; and Lam persuaded that 
to a similar cause may be chiefly attributed the gnats so often found in continental 
towns not situated near to canals or stagnant pools, ‘The remedy is equally obvious and 
easy. Wither open water-tubs and cisterns should be proscribed, or a few small fish 
keptin them to destroy the larva of the gnats a9 fast as they breed. ‘Trees being 
