224 THE TROPICAL WORLD. 



' child of the night,' disappears at sunrise, and then makes place 

 for the matutinal Tempranero. As all these winged tormentors 

 spend the greater part of their lives in the water, we cannot 

 wonder that their numbers diminish as the distance from the 

 hanks of the rivers intersecting the forests increases. Their 

 favourite resorts are the places where their transformation 

 takes place, and where they on their part are soon about to lay 

 their eggs. The mosquito clouds hover only above or near the 

 waters, and it would be a great error to suppose that the vast 

 forests extending between the river valleys are all equally 

 infested with tliis insect plague. 



From time to time the mosquitoes migrate like the social 

 stentor monkeys. Formerly no other Culex was known at 

 Simiti on the Magdalen river but the small species called 

 Zejen. The people slept unmolested, for the Zejen is a 

 diurnal insect. But in 1801 the great blue-winged Zancudo 

 made his appearance in such numbers that the poor inhabitants 

 of Simiti could find no rest at night. 



Slight differences of climate or food seem to have an 

 influence on the intensity of the poison which the same species 

 discharges through its serrated proboscis. One cannot refrain 

 from smiling at the disputes of the missionaries about the size 

 and voracity of the mosquitoes in different parts of the same 

 river. In a land so completely severed from the rest of the 

 world, this forms the favourite subject for conversation. 'How 

 much I pity you,' said the missionary from the falls as he took 

 leave of his colleague at the Cassiquiare ; ' you are like me, alone 

 in this land of jaguars and monkeys, but as to my mosquitoes 

 I can boast that one of mine is a match for three of yours.' 



This unequal voracity of the insects in different places, this 

 various intensity of poison in the same species, are very re- 

 markable, but similar phenomena are met with in the classes of 

 the large animals. In Angostura the crocodile attacks man, 

 while in New Barcelona people bathe in his presence without 

 fear. The jaguars on the isthmus of Panama are cowardly when 

 compared with those of the Upper Orinoco ; and the Indians 

 know very well that the monkeys from one part of the country 

 can easily be tamed, while individuals of the same species 

 caught elsewhere will rather die of hunger than submit to 

 captivity.' 



