264 THE CANADIAN NATURALIST. [^^g- 



Jamica the proportion is 1 to 8, in Otaheite it is 1 to 4, and in St. 

 Helena and Ascension nearly 1 to 2. In the temperate zone, 

 Humboldt gives the proportion of ferns to phanerogamous plants 

 as 1 to 70. In North America ihe j)roportion is 1 to 35 ; in France 

 1 to 58 ; in Germ my 1 to 52 ; in the dry parts of southern Italy as 

 1 to 74 ; and in Greece 1 to 84. In colder regions the proportion 

 increases ; that is to say, ferns decrease more slowly in number than 

 phanerogamous plants. Thus in Lapland the proportim is 1 

 to 25 ; in Iceland 1 to 18 ; and in Greenland 1 to 12. The pro- 

 portion is least in the middle temperate zone, and it increases both 

 towards the equator and towards the poles ; at the same time it 

 must be remarked, that ferns reach their absolute maximum in 

 the torrid zone, and their absolute minimum in the arctic zone." 



Canada consists of a belt of land, lying to the north of the St. 

 Lawrence River and the Great Lakes. By these it is separated, 

 along nearly the whole extent of its south-eastern and western 

 boundaries, from the northern United States, which thus enclose 

 Canada on two sides. A striking resemblance, amounting almost 

 to identity, is therefore to be looked for in the floras of the two 

 countries. Yet species appear in each that are absent in the 

 other. 



The species of ferns and filicoid plants which are certainly 



Canadian, amount to 63 



Of these there inhabit the Northern States, 58 



Do. do. Southern States, 38 



Do. do. Europe, 36 



The following table is designed lo show some of the geographical 

 relations of our Canadian ferns. The first column (I.) refers ex- 

 clusively to the occurrence of the species within the Canadian boun- 

 dary. The plus sign ( + ) indicates that the species is general, or 

 at least does not show any decided tendency towards the extreme 

 eastern or western, or northern or southern parts of the Province. 

 The letters N, S, E, W, &c., variously combined, indicate that the 

 species is so limited to the corresponding northern, southern,eastern 

 or western parts of the province, or at least has a well-defined ten- 

 dency to such limitation. The mark of interrogation (?) signifies 

 doubt as to the occurrence of the species. The second column (II,) 

 shows what Canadian species occur also in the Northern States, that 

 is the region embraced by Gray's Manual ; and the third column 

 (IIL) those that extend down south into Chapman's territory. 

 The fourth column (IV.) shows the occurrence of our species iu 



