^86 Barom Humboldt on the Lam which are observed 
zone : it almost dii^appears between the tropics^ excepting at the 
summit of the mountains* The group of Rubiaceae with oppo- 
dte leaves and stipules, belong very peculiarly to the equinoc- 
tial region. M. Kunth has divided the great family of Rubia- 
tjeae into eight groups, one^of which, that of the Coffeaceae, forms 
in our herbaries a third part of the whole Rubiaceae of equinoc- 
tial America. {Nov* Gen, vol. hi. p. 341 .) 
EuPHORBiACEi:. rr Trop. America, ; India and New 
Holland, ; Western Africa, {Congo, p. S 5 .) Temp. 
France, ; Germany, Frig. Lapland, j Jg. 
EmcE^andRHODODENDRA. = Trop. America, 5. Temp. 
France, ; Germany, ; North America, /j. Frig. Lap- 
land, jV- 
Ament ACE^. = Trop. America, ^ J5. Temp. France, ^*<5 ; 
Germany, ; North America, ^ Frig. Lapland, /j. 
Umbellifer^. = almost none under the tropics to the 
height of 1200 toises; but, on taking both the plains and high 
mountains in equinoctial America, ; under the temperate 
zone much more numerous in the Old than in the New Conti- 
nent. France, ; North America, ; Lapland, 
Oh comparing the two worlds, we find in general in the New 
World, under the equatorial zone, fewer Cyperace^ and Rubia- 
ceae, and more Compositae ; under the temperate zone, fewer 
Labiatae and Cruciferas, and more Compositae, Ericae, and Amen- 
taceae, than in the corresponding zones of the Old World. The 
families which increase from the equator toward the pole (ac- 
cording to the fractional method), are the Glumaceae, the Eri- 
ceae, and the Amentace^. The families which decrease from 
the pole toward the equator are the Leguminosae, the Rubiaceae, 
the Euphorbiaceas, and the Malvaceae. The families which ap- 
pear to attain the maximum under the temperate zone, are the 
Compositae, tile Labiatae, the Umbelliferae, and the Cruciferae. 
I have thrown together the principal results of this work in 
one table ; but I enjoin naturalists to have recourse to illustra- 
