SUMMAET AND ANALYSIS OF THE FLOEA. 201 



Numbers and Percentages of the Mexican and Central-American species of the primary 

 divisions of Phanerogamic Plants: total 11.626. 



Dicotyledons 9,125 species. 78*5 per cent. 



Monocotyledons 2,501 21-5 



11,626 100-0 



Number and Percentage of species of Vascular Cryptogamic Plants in the total 



12,233 of Vascular Plants. 



Cryptogams 607 species. 5-0 per cent. 



Filices alone • . 545 js 4.5 



Or 95 per cent, of Phanerogams and 5 per cent, of Vascular Cryptogams. 



By way of comparison it may be stated that for the whole of Australia the proportion 

 of monocotyledons to dicotyledons is as 1 to 4*4, and for Europe as 1 to 4-8, whereas 

 ours is about as 1 to 3*6. On the other hand, the proportion of vascular cryptogams 

 to the phanerogamic plants in our flora is very much higher than in the Australian and 

 the European floras. 



Ordinal Distribution. 



This is naturally followed by an arrangement of the orders in numerical sequence in 

 relation to the number of species in Mexico and Central America, adding the per- 

 centages of each in the whole ; the number of genera, which by no means follows that 

 of the species ; and the most striking or important features in the general distribution of 

 the orders. Except Europe, Australia is the only large country the flora of which has 

 been sufficiently elaborated to enable us to institute comparisons in the sequence of 

 the predominance of the whole of the orders ; and the figures in brackets preceding 

 the orders are extracted from one of Baron Mueller's latest contributions to Australian 

 botanical geography*. Many comparisons with other countries besides Australia are 

 made in the discussion on the general distribution of the larger natural orders some 

 pages further on. Where, as in the distribution of the Palmar, the phrase temperate 

 latitudes is employed, some members of the order inhabit altitudinal temperate regions 

 within the tropics. 



All the orders represented in Australia by an equal number of species are indicated as 

 occupying the same position in the sequence, otherwise some of them would be removed 

 a considerable distance from their true positions, because, in one instance, as many as 

 fourteen orders are represented by the same number of species. 



* ' Systematic Census of Australian Plants.' Third Annual Supplement, 1886, p. 6. 



