Geographical Distribution of Insects. 95 



zoologist may have an intimate acquaintance both with the 

 external characters and internal organization of a species, 

 and still have occasion to lament that he is in ignorance of 

 some of the most interesting considerations that attach to its 

 history. 



It will readily be conceived, that the distribution of the 

 lower animals would be still less attended to. Creatures 

 which seemed to owe their birth to some fortuitous influences, 

 or to effloresce, as it were, from the very surface of the soil, 

 could scarcely be supposed to be subject to the same laws 

 which affected the condition of superior natures. Even down 

 to the time of Linnaeus and Fabricius, an era from which we 

 are wont to date the rise of all true zoological knowledge, but 

 little had been done in furtherance of this department. It 

 may even be questioned, in regard to insects especially, whe- 

 ther the labom'S of the distinguished individuals just named 

 did not tend, in some respects, to embroil rather than illustrate 

 the subject of their geographical distribution. So habitually 

 disregardful were they of determining the precise local habi- 

 tations of the species, that we are often left in doubt even as 

 to which of the hemispheres they belong. The phrase " ab 

 Indis," which occiu-s so frequently in their works, may mean 

 either the East or West Indies, and is occasionally used with 

 such latitude of meaning as to be synonymous with exotic, or 

 extra-European. This want of precision, however, it must 

 be admitted, was in some measure unavoidable, as the con- 

 signments of insects which they received were generally col- 

 lected indiscriminately from foreign countries, and blended 

 together in inextricable confusion. Fabricius, at least, appre- 

 ciated the value of accuracy on this point, and lays down some 

 general principles, in his Philosophia Entomologica, regarding 

 insect geography, which may be considered as the first formal 

 attempt to place the subject on a sound footing. By the time 

 of Latreille, a gi-eat accumulation of localities had taken place, 

 the accuracy of which could be implicitly relied on, and he 

 was enabled to deduce from the consideration of them certain 

 general laws, which appeared to him to regulate the distribu- 

 tion of insect life. Of his treatise on this subject it is unne- 

 cessary to give any account in this place, as a translation of 



