M. Latreille on the Geographical Distribution of' Insects. S7T 
insects proper to colder districts, to Germany, &c. and that the 
warm and sandy soils, situated to the south and east of Paris, 
present some species belonging to more southern regions. 
6. We shall divide the Old and New Continent into zones* 
spreading successively in the manner of meridians, and of which 
the breadth is measured by a portion of a circle parallel to the 
Equator. The species proper to one of these zones disappear 
gradually, and give place to those of the following one ; so that 
from one space to another, the prevailing species, or even the 
totality undergo a change. I compare these changes to that 
series of horizons which the traveller discovers, in proportion as 
he removes from his first point of departure. 
Sweden has many species of insects which are particular to it, 
and of which some are banished to its most northern provinces* 
such as Lapland. But its southern district, for example, Sca- 
nia, offers, though in small quantities, many insects of Germany. 
France, as far as the 45° or 44° of latitude, produces many 
species also found in these countries. It appears that the Rhine 
and its eastern mountains, form, in regard to some other spe- 
cies, a sort of frontier which they have not crossed. The first 
of those which are proper to the warm countries of western Eu- 
rope, shew themselves towards the inferior course of the Seine* 
precisely at the point where the vine begins to flourish in the 
plains, without the assistance of local circumstances. The Ateu~ 
chus flagellatus, the Mylabris chicorii , the Mantis religiosa , 
the Ascdlaphus italicus , & c. announce this change. It is still 
more manifest at Fontainebleau, and the environs of Orleans, 
where, besides those just mentioned, we find the following spe- 
cies : Phasma Rossii , Mantis pagana, and Sphinx celerio , &c. 
But these insects, if I may so express myself, are only the 
forerunners of such as are proper to the truly southern coun- 
tries. One recognises the domain of these last, on the appear- 
ance of some other species of Cicada , Mantis , Zonitis , AMs? 
Scaurus , Termes , &c., but more especially in the presence of 
the Scorpio Europaus, and the Ateuchus sacer *. The cub 
* The butterflies of the division called Equites or Knights, have also their 
principal seat in warm countries, and especially between the Tropics. Those which 
Linnaeus has named Trojans , are proper to America, and that part of Asia which 
lies beyond India. 
