370 Geographical Distribution of Insects. 



not exist, life is vigorously sustained by numerous substitutes. 

 The silk-worm, in default of its favourite mulberry leaves, thrives 

 well upon lettuce and other plants. 



In regard to North American species especially, Nature her- 

 self points out, that the character of the climate, in relation to 

 the development of insect life, possesses many attributes in com- 

 mon with that of Britain and other portions of Europe. Many 

 of the species are alike common to both continents, and an in- 

 teresting and instructive list might be drawn up in illustration 

 of this community of kinds. This, however, must be done from 

 the specimens themselves, and not from books of travels, or 

 other general sources, the authors of which, till of late years, ap- 

 plied the supposed synonyms of animals always in a vague, and 

 frequently in an inaccurate manner. This reproach is now re- 

 moved by the admirable descriptive catalogues which, in the 

 form of natural history appendices, are annexed to or follow the 

 publication of all voyages of discovery or other records of travel. 



It is in considering the widely extended distribution of many 

 of the forms of insect life, that the subject of llie geographical 

 allotment of animals is seen under its most curious and truly 

 wonderful aspect. A discovery ship under the guidance of 

 brave men, surmounts with difficulty the terrors of the ocean, 

 and after being months on the trackless main, and some thou- 

 sand miles from any of the great continents of the earth, she 

 arrives at last, and accidentally, at some hitherto unknown 

 island of small dimensions, a mere speck in the vast world of 

 waters by which it is surrounded. She probably finds the 

 " Lord of the creation" there unknown, — but though untrod by 

 human footsteps, how busy is that lonely spot with all the other 

 forms of native life ! Even man himself is represented not un- 

 aptly by the sagacious and imitative monkeys, which eagerly 

 employ so many vain expedients to drive from their shores what 

 they no doubt regard as merely a stronger species of their race. 

 " Birds of gayest plume" stand fearlessly before the unsympa- 

 thizing naturalist, and at every step of the botanical collector, 

 the most gorgeous butterflies are wafted from the blossoms of 

 unknown flowers, and beautify the " living air" with their many 

 splendid hues ; yet how frail are such gaudy wings, and how 

 vainly would they now serve as the means of transport from 



