498 
GEOGRAPHY. 
BOOK V. 
ratio as has any where been observed ; while the proportion 
of grasses is nearly double that of any part of the world. 
Parry's Appendix.'] The proportion varies from -J- to ^ in 
different parts of the tropics. Among 3880 phanerogamous 
plants found in equinoctial America by Bonpland and myself, 
there are 654 Monocotyledones and 3226 Dicotyledones ; 
here, therefore, the great division of Monocotyledones forms 
^ of phaenogamous plants. According to Brown, this propor- 
tion is in the old world (India, equinoctial Africa, and New 
Holland) 3^. Under the temperate zone it is found to be -J ; 
France 1 : 4f ; Germany 1:4^; North America, according to 
Pursh, 1 :4|^; kingdom of Naples 1 : 4^^ ; Switzerland 1 : 41; 
Great Britain 1: 3J; [Sweden 1 : 3^0 ; but in Sicily, accord- 
ing to Presl, it is 1 : 5tV? which is much too high]. In the 
frozen zone y. 
" Glumaceji: (that is to say, the three families of Junceae, 
Cyperaceae, and Gramineae united). — Trop. j Temp. ^; 
Frozen ^. This increase towards the nortli is due to the 
greater prevalence of Junceae and Cyperaceae, which are much 
more rare, as compared with other phaenogamous plants, in 
the temperate and torrid zones. Comparing the species of 
these three families, we find that Gramineae, Cyperaceae, and 
Junceae are in the tropics as 25, 7, 1 ; in the temperate parts 
of the old world as 7, 5, 1 ; within the polar circle as 2f, 25-, 
and I. In Lapland there are as many Gramineae as Cype- 
raceae ; thence, towards the equator, Cyperaceae and Junceae 
diminish much more than Gramineae. The form of Junceae 
almost disappears in the tropics. 
" JuNCE^ alone. — Trop. - Temp. , (Germany -g^-j, 
France -gV)? [Sicily 3-^3^] ; Frozen ^Vj [Melville Island 3V]. 
" CvPERACEiE alone. — Trop. America scarcely 5V? Western 
Africa y^s, India ^^w Holland ; Temp, perhaps 2V5 
(Germany -iV, France, according to De Candolle, Hen- 
mark iVj) [Sweden rather more than ^V? Sicily 5V] ; Frozen -J, 
in Lapland and Kamtschatka ; [Melville Island -yj~\. 
" Gramine^ alone. — Trop. I have always supposed but 
Brown finds for western Africa -^-^^ for India tV j and Horne- 
man makes the proportion of Guinea ; Temp. Germany 1V5 
France iV? [Sweden not quite Sicily tV] ; Frozen -xVj 
M elville Island nearly 
