492 
MR. G. BENTHAM ON COMPOSIT E. 
Genera. Tropical-American representatives. | Tropical Old-World representatives. 
COREOPSIS ......... 3 or 4 Peruvian species near the | About 8 species, East-African ( Presti- 
African, and nearly 40 diverging, | naria), near the Peruvian. 
chiefly North-American eat 
Mexican. 
Connexions ...... Bidens (Psilocarpea) nearly 40 spe- | Bidens (Psilocarpea) 2 species (colo- 
cies, Cosmos 10 species, Dahlia 4, | nists?), Glossogyne 5 species (East- 
Hidalgoa 2, Isostigma 5, Thelesperma | Asiatic and Australian), Guizotia 3, 
4 or > species, all tropical or subtro- | and Microlecane 1 (African). 
pical. : 
CHRYSANTHEL- |1 species tropical-American, 1 Gala- | 1 species, African and Asiatic, pro- 
LUM. pagos. bably the same as the American. 
Connexions ...... Heterospermum 1 species. Glossocardia 1 species, Asiatic. 
A first rapid glance over the above Table shows the general 
American character of the whole. For the most part the African 
and Asiatic species sections or genera are few and disconnected, 
the corresponding American ones numerous and closely connected 
on all sides with American allies. And yet the endemic Old- 
World races from species to genera are too numerous and varied 
to admit of the supposition that they can ever have migrated from 
America and become extinct in their birth-place. It would seem 
rather that whatever may have been the cause of the parent 
Wedelie, Sclerocarpi, Melanthere, &c. having once been esta- 
blished both in Africa and in America, or in some land at one or 
different times in connexion with the two continents, they had by 
long isolation become more and more differentiated in the two— 
that in America they have as races prospered and multiplied in 
every direction and possibly retained many of their very early 
forms ; whilst in the Old World they have found less genial cir- 
cumstances, they have for the most part dwindled away, a far 
greater proportion than in America have become extinct, and the 
few local representatives we now see are probably in the course of 
extinction. And this will, I believe, be found to be more particu- 
larly the case with the African races, Here, more perhaps than 
in any other part of the globe, in Composite as in so many other 
orders, we may fancy we see the scattered remains of ancient races 
dwindling down to their last representatives. 
It is not so, however, with a few of the races included in the 
above Table, especially some of those which have rather more of an 
Asiatic than an African character. The sections Tephrodes, 
Cyanopis, and Gymnanthemum of Vernonia, the section Wollas- 
tonia of Wedelia, the genera Ethulia and Chrysanthellum may be 
flourishing and increasing races, which have already been much 
differentiated in the Old World and are likely to become more so; 
the two last-named, as well as Vernonia (Tephrodes) conyzoides, are 
