S72 M. Latreille on the Geographical Distribution of Insects. 
consideration the height above the sea of the places where he 
collects his specimens, and he will also observe with care the 
mean temperature. 
Naturalists, as well as geographers, have divided the surlace 
of the earth into different climates. The latter have taken for 
a base the progressive differences in the longest duration of the 
natural day ; the former have founded their divisions on the 
mean temperature of the regions proper to animals and ve- 
getables. In the Philosophia Entomologica of Fabricius, the 
acceptation of the word Climate is general, and embraces the 
universality of the habitations of insects, or of all the animals 
with articulated feet. He divides climate into eight stations, or 
particular subclimates, viz. The Indian , the austral , the Medi- 
terranean, the northern , the eastern , the western , and the alpine. 
But it is easy to see, by the enumeration of the countries which 
belong to each of them, that these divisions are not always esta- 
blished on positive documents, and that it would be necessary, 
if one follows rigorously the principle on which they rest, the 
mean temperature, that some of them be suppressed. The sub- 
climate which is called Mediterranean , comprehends the coun- 
tries adjacent to the Mediterranean Sea, and also Media and 
Armenia. The boreal, or northern, extends from Paris to Lap- 
land. The eastern is composed of the north of Asia, of Siberia, 
and of the cold and mountainous part of Syria. The western 
includes Canada, the United States, Japan, and China. This 
simple expose may suffice to convince us, that there is much 
that is arbitrary in these divisions. Several of these countries 
actually have the same mean temperature ; yet they are not 
ranged under the same climate. But besides that these distinc- 
tions are scarcely of any use to science, since the places in which 
the mean temperature is the same, produce different animals, it 
is impossible, in the actual state of our knowledge, to insure such 
divisions of climate on a solid basis. The different elevations 
of the soil above the level of the sea, its mineralogical composi- 
tion, the variable quantity of water which moistens it, the mo- 
difications which the mountains, by their extent, their height, 
and their direction, produce on its temperature, the forests 
more or less great by which it is covered, the influence exercised 
on its temperature by that of neighbouring climates,— are the 
elements which render complicate these calculations, and which 
