( 370 ) 
Art. XI X.— -On the Geographical distribution of Insects *. By 
M. Latreille. 
OnE of the most curious subjects in Entomology, and which 
has not hitherto been treated of, the determination of the cli- 
mates proper to the different tribes of insects, is nearly connected 
with the history of their nutrition. For, in fact, since the Author 
of Nature has spread living beings over all the points of the sur- 
face of our globe, capable of maintaining them, and since these 
beings vary with the climates, it is necessary that the alimentary 
substances of animals should vary equally ; and thus, as well as 
the animals themselves, should have a geographical circumscrip- 
tion. 
Independently of such consideration, the temperature which 
fits the developement of one species, is not always proper for 
that of another ; thus, the extent of country which certain spe- 
cies occupy, has necessarily determinate limits which they can- 
not exceed, at least suddenly, without ceasing to exist. 
These principles lead to another consequence ; where the em- 
pire of Flora terminates, there also the dominion of animal life 
is at an end. The animals which maintain themselves on vege- 
tables, cannot live in places entirely steril ; and those which are 
carnivorous, would be equally deprived of alimentary matter, in 
the absence of those creatures of which they make their prey ; 
therefore, neither tribe can be there established. 
The observation teaches us, that the countries the most abun- 
dant in animals with articulated feet, more especially insects, are 
those of which the vegetation is the richest and the most rapid- 
ly renewed Such are the effects of a warmth strong and long 
sustained, of a moderate moisture, and a varied soil. The near- 
er, on the contrary, that one approaches the limit where snow 
and ice are eternal, whether by advancing towards the Poles, or 
by ascending mountains, the more is the number of plants and in- 
sects diminished. Thus, Otho Fabricius, who published a 
; ( ' 
Abridged from the Introduction a la Geographic Generate des Arachnides et 
des Insectes , ou des Climats propres a ces animaux Memoir es du Museum d' His- 
tone Naturelle , vol. iii. 
