INTRODUCTION. xix 
Relative numbers of Orders, Genera, and Species in India, Mexico, 
North America, and Australia. 
Orders. Genera. Species. 
India ........ 02.2008. 174* 2271 13647 
Mexico .............. 162* 1794 11626 
North America ........ 158* . 1513 9403 
Australia ............ 154 1335 8575 
Percentages of Dicotyledones (including Gymnospermex) and Monocotyledones 
in the four areas and in Europe. 
Dicotyledones. Monocotyledones. 
India ......... ee eee. 76°57 23°43 =100-00 
Mexico .............. 78°50 21:50 =100-00 
North AmericaT ...... 80°62 19°38 =100-00 
Australia ............ 81:50 18°50 =100-00 
Europe $.........0.06- 82°70 17°30 =100-00 
The mean proportions of the five countries are 79:97 dicotyledons and 20-03 per cent. 
monocotyledons, against 81°29 and 18°71 for the whole world, showing that the nume- 
rical proportions do not greatly vary for large areas, no matter how distant they are, 
nor how dissimilar is their vegetation as a whole; yet it is hardly necessary to add that 
very different proportions exist in smaller areas. Generally speaking, the drier the 
region the smaller the proportion of monocotyledons, and the greater the proportion of 
them bulbous plants. Maximowicz § in an analysis of the vegetation of different parts 
of Central and Eastern Asia gives the percentage of monocotyledons in the Phanerogamia 
as 14:1 in Tangout, or Northern Tibet, and 26-1 in Japan. But, as already hinted, 
figures of this kind convey no very definite information, inasmuch as they embody no 
idea of individual development, as a species of palm, bamboo, or banana of the tropics 
counts no more than a snowdrop, daffodil, or small grass of the temperate regions. 
Alphonse De Candolle ||, who presents very numerous statistics of the proportions of 
monocotyledons and dicotyledons in small areas, strongly insists on this point. It should 
be borne in mind that all statistical analyses of floras are to a great extent illusory, and 
can only be properly appreciated after a careful consideration of the composition of the 
elements. This fact is illustrated in the following somewhat detailed examination of 
the preceding table. — 
One thing brought into great prominence by this table is the large number of 
* Including the Fumariaces, treated as a suborder of the Papaveracee in the ‘Genera Plantarum.’ 
+ Calculated from the second edition of Oyster’s ‘ Catalogue of North American Plants,’ after deducting the 
introduced species. 
+ Calculated from the numbers given in Nyman’s ‘Conspectus Flore Europes,’ p. 848, excluding the 
“* subspecies.” 
§ Bulletin du Congrés International de Botanique et @Hortcultiure 4 St. Petersbourg, 1884, p. 158. 
| Géographie Botanique Raisonnée, ii. p. 1166. 
c2 
