76 TROPICAL NATURE, AND OTHER ESSAYS. 



Peculiar Habits of Tropical Butte^iflies. — The habits 

 of the butterflies of the tropics offer many curious 

 points rarely or never observed among those of the 

 temperate zone. The majority, as with us, are truly 

 diurnal, but there are some Eastern Morphidae and the 

 entire American family Brassolidae, which are cre- 

 puscular, coming out after sunset and flitting about the 

 roads till it is nearly dark. Others, though flying in 

 the daytime, are only found in the gloomiest recesses of 

 the forest, where a constant twilight may be said to 

 prevail. The majority of the species fly at a moderate 

 height (from five to ten feet above the ground) while a 

 few usually keep higher up and are difficult to capture ; 

 but a large number, especially the Satyridse, many 

 Erycinidse, and some few Nymphalidse, keep always 

 close to the ground, and usually settle on or among the 

 lowest herbage. As regards the mode of flight, the 

 extensive and almost exclusively tropical families of 

 Heliconidse and Danaidse, fly very slowly, with a gentle 

 undulating or floating motion which is almost peculiar 

 to them. Many of the strong-bodied Nymphalidse and 

 Hesperidse, on the other hand, have an excessively rapid 

 flight, darting by so swiftly that the eye cannot follow 

 them, and in some cases producing a deep sound louder 

 than that of the humming-birds. 



The places they frequent, and their mode of resting, are 

 various and often remarkable. A considerable number 

 frequent damp open places, especially river sides and 

 the margins of pools, assembling together in flocks of 

 hundreds of individuals ; but these are almost entirely 

 composed of males, the females remaining in the forests 

 where, towards the afternoon, their partners join them. 



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