434 THE CANADIAN NATURALIST. [D 



ec. 



grasses bear very nearly the same relations to flowering plants — 

 1 -1 2th to l-13th — in the three divisions of country mentioned, 

 xlmong other orders there are some marked differences in the 

 proportions as they are exhibited in the different geographical 

 regions ; — in some the species proportionably increase from Canada 

 southward ; in others, the reverse of this is the feature. The five 

 examples cited below will illustrate these particulars : — 



Ontario Northern United 



and Quebec. States. States. 



Leguminoseas i-2gth i-2ist i-iSth 



Euphorbiaceae 1-95^ i~72nd i-58th 



Rosacea? i-25th i-32nd i-40th 



Cruciferae i-3ist i-39th i-49th 



Ericaceae J-34th i-38th i-43rd 



Among the smaller orders there are instances quite as marked. 

 Convolvulacese increases from eight species within our limits to 

 twenty-four in the Northern States, and forty-one in the whole 

 Union ; and the Malvaceae are similarly augmented from eight to 

 twenty-two and forty-four ; whilst in Cupuliferae the species, in 

 which are sixteen, twenty-three, and thirty-one, respectively, the 

 numbers proportionally diminish. These circumstances tend, of 

 course, to indicate the well-known facts, that, whilst some of the 

 orders mentioned are semi-tropical and southern temperate, others 

 are more abundant in the northern temperate regions of America. 



The number of species occurring within our limits in each of 

 the large orders is indicated below. To admit of a comparison 

 being more easily made, the numbers in the same orders in the 

 United States are placed in parallel columns. 



Ontario Northern United 



and Quebec. States. States. 



Composite 194 324 481 



Cyperaceae 155 248 336 



Graminae 124 212 287 



Rosaceae 65 81 92 



LeguminosEe 55 120 199 



Cruciferae 51 65 74 



Ericaceae 47 68 84 



Labiatae 47 76 108 



Orchidacese 46 57 71 



Scrophulariaceae 44 66 94 



Filices 44 57 76 



Liliaceae 42 62 78 



Caryophllaceae 34 33 70 



Polygonacese 34 38 54 



Umbeiliferae 28 45 58 



To somewhat complete the parallel drawn, it will be useful to 

 bring to view the number of species in the more important 

 genera of Ontario and Quebec and of the Northern States. To 

 extend the comparison to the flora of the Southern States may 

 diminish its interest, as many of the conspicuous genera there are 



