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 or Simulia flying in the day; the Temporaneros, 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 Stomoxys before noticed. 1 



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 Kollar'swork on Obnoxious Insects ; a translation 

 of part of which, by the Misses London, has recently been published. 

 The work of Pohl and Kollar 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 2 ; nor that the inhabitants of various cities, as Mouflfet has col- 

 lected from different authors 3 , 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. 4 



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, E. 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. Eccl 1. ii. c. 30. 



3 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 I am 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 remedv is equally obvious and 

 easy. Either open water-tubs and cisterns should be proscribed, or a few small fish 

 kept in them to destroy the larvae of the gnats as fast as they breed. Trees being 



