464 Natural-Historical Collections. 
considered the Cedrelee to be only a tribe of the Meliaceg, under which he ad- 
mitted two others, the Meliee and Trichilee. MM. Blume, Fuhlrott, and 
Reichebac, have since made other innovations. This was the state of things 
when M. Adrien de Jussieu undertook his monographic work, the last result of 
which has been the division of the Meliacee into two families,—the Meliacee 
properly so called, and the Cedrelace@,—and the subdivision of each into two na- 
tural tribes, viz. the former into Meliee and Trichilee, and the latter into Swie- 
tenie and Cedrelee. 
The following conclusions are also derived from the researches of M. de Jus- 
sieu -— 
i. The Meliacee become more and more frequent, in- proportion as we ap- 
preach the tropics; and they occupy, besides the equatorial zone, that which M. 
Mirbel has named the transition temperate zone. 
2. There is a striking relation between the affinities of the genera and their 
habitations. 
This accordance between the geographical distribution of genera and their 
botanical distribution, merits the attention of philosophers, because we observe 
it more or less in many other families, according as they are more deeply studied ; 
and it may serve for the basis of important considerations. 
In examining how the meliacee are distributed over the surface of the globe 
with relation to each other, the author has marked the following agreement be- 
tween the geographical and the botanical distribution. If the genera be dis- 
posed in a certain series, which, according to their characters, the author consi- 
ders to be the most natural, and the country of each be noted, we shall find that 
the order in which these countries follow each other, designs upon the map a 
very regular itinerary. Thus, he divides the whole group into two families, the 
meliacee and the cedrelacee, and each of these into two tribes. And we fihd 
that the series of genera of the first tribe of meliacee, passing from southern 
Europe, leads us successively through Africa, its southern isles, Asia, the Ar- 
chipelagos which cennect Asia with New Holland, and stops in this last conti- 
nent. The series of genera of the second tribe, returning from the South Sea 
islands, retraverse New Holland, the Archipelagos, Africa, and arrive in equato- 
rial America, where its maximum is displayed. 
A similar statement applies to the other family, whose less numerous species 
also design in their series two retrogade lines. Thus, a traveller who shall go 
from Europe to the Antipodes and return, following the route which we have in- 
dicated, and who, during his journey, shall collect all the plants of this family, 
will find that he has gathered them nearly in the order of their affinity. 
It is not useless, moreover, to remark, that this frequent relation which we re- 
mark between the habitations and the characters of the plants, frequently does 
not show itself till after a most scrupulous investigation, founded on an intimate 
inquiry into the modifications of all the organs of plants, into characters of 
families, when the degree of value has been assigned to each of these characters. 
Thus the labours of classification are intimately related, in our day, to organ- 
ography and vegetable statistics. 
These preliminary considerations being established, the author gives a detailed 
description of the characters proper to the family of meleacee ; and then occu- 
pies himself with the cedrelacee. 
The iatter family is interesting from containing great trees, whose odorous 
wood, compact structure, and beatiful colour, little liable to alteration, make 
them eminently fitted for cabinet work. It will be sufficient to cite as an ex- 
ample the swietenia mahogani of America, which furnishes the beautiful maho- 
gany wood. 
