54 M. Latreille on the Geographical Distribution of Insects. 
in the western world, they are scarcely found, until we reach 
the vicinity of 43° north latitude. The genera Scorpio^ Ci- 
cada, Mantis, are always our guides. When one reflects 
on the physical constitution of America, when we consider 
that its soil is much irrigated, considerably mountainous, cover- 
ed with great forests, and that its atmosphere is very moist, we 
may conceive without difficulty, that certain genera of insects of 
the Ancient Continent, which affect dry, sandy, and very warm 
situations, such as Anthia, Pimelia, Erodius, Brachicerus, he. 
would be unable to exist on the rich, humid, shaded soil of the 
New World. Also the number of carnivorous coleoptera, is pro- 
portionally less on the New than the Old Continent, and their size 
is often inferior. The scorpions of Cayenne and of other equi- 
noctial countries, are scarcely larger than that species of the 
south of Europe called occitanus. They are, then, far from 
equalling in size the African species called Afer, which is almost 
as large as our river cray-fish. But America yields not to the 
most fruitful countries of the ancient Continent, in regard to the 
species which live on vegetables, especially of the Lepidopterous or- 
der, and in the genera Scarahicus, Chrysomela and Cerambyx, he. 
It is also abundant in the wasp and ant tribe ; in orthopterous in- 
sects and spiders. The southern parts of China, however, and the 
Moluccas, appear to preserve a kind of superiority, in giving birth 
to such insects as the Papilio priamus, the Bombyx atlas, he, 
of which the dimensions surpass those of the American Lepidop- 
tera. One fact which I ought not to omit, is, that Europe, 
Africa, and Western Asia, have scarcely any insects of the ge- 
nus Phasma or spectres, and those few very small ; whilst those 
of the Moluccas and South America are of a very remarkable 
size. The atmospheric and habitual humidity of the New Con- 
tinent, its narrow and prolonged form, the vast extent of the 
seas which environ it on all parts, and the nature of its soil, fur- 
nish us with an explanation of the disagreement which is to be 
observed between its climates and those of our hemisphere, con- 
sidered under the same parallel. The New Continent is to the 
Ancient World, what England is to a great part of Europe. Nor- 
mandy and Bretagne, compared with the provinces of France 
situated to their east, could also furnish us with analogous re- 
semblances. 
