Synopsis of Canadian Ferns and Filicoid Plants. 103 



From these statements it will be seen tLat we have our due 

 share of ferns in Canada. 



The wdiole number of ferns in all the American States, 

 and the British North American Provinces, is estimated, in 

 a recent letter from Mr Eaton, as probably over 100. 



In the British Islands there are about 60 ferns and filicoid 

 plants. In islands of warmer regions the number is greatly 

 increased. Thus Mr Eaton's Enumeration of the true ferns 

 collected b}^ AY right, Scott, and Hayes, in Cuba, embraces 

 357 species. The proportions of ferns to phanerogamous 

 plants in the floras of different countries are thus indicated 

 by Professor Balfour, in the " Class Book of Botany," page 

 998, ^ 1604: — " In the low^ plains of the great continents 

 within the tropics ferns are to plianerogamous plants as 1 to 

 20 ; on the mountainous parts of the great continents, in 

 the same latitudes as 1 to 8 or 1 to 6 ; in Congo as 1 to 27 ; 

 in New Holland as 1 to 26. In small islands, dispersed over 

 a wide ocean, the proportion of ferns increases ; thus, while 

 in Jamaica the proportion is 1 to 8, in Otaheite it is 1 to 4, 

 and in St Helena and Ascension nearh^ 1 to 2. In the 

 temperate Zone, Humboldt gives the proportion of ferns to 

 phanerogamous plants as 1 to 70. In Nortli America the 

 proportion is 1 to 35 ; in France 1 to 58 ; in Germany 1 to 

 52 ; in the dry parts of South 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 phane- 

 rogamous plants. Thus, in Lapland, the proportion is 1 to 

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

 proportion 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 Eiver 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, wdiich 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. 



