Section IV, 188*7. [ 189 ] Trans. Eoy. Soc. Canada. 



XVI. — Arctic Plants grovnng in New Brunswick, with Notes on their Distribution. 

 By Eev. James Fowlek, M. A., Kingston. 



(Communicated by Jfr. J. Fletcher, May 25, 1S87.) 



The laws governing the geographical distribvition of plants have long been a subject 

 of earnest enquiry among naturalists, but they are as yet far from being fully understood. 

 The general triith, that the carpet of vegetation which covers the surface of the earth, is 

 most densely woven at the equator, and diminishes in density and beauty as we recede 

 towards the poles, and that this arrangement depends very largely upon temperature, has 

 long been known. But it is also a well recognised fact that the limits of any given species 

 or genus of plants, across a continent, are not bounded by the parallels of latitude. The 

 Arctic flora of Western Europe is vastly richer than that of Arctic Asia— Lapland being 

 covered with a denser robe of vegetation than any other province in the Arctic regions, and 

 containing about three-fourths of all the species found within the polar zone. Arctic Asia 

 is distinguished by its extreme poverty of species, being inhabited by less than one-third 

 of the phœnogamous species found in the Arctic area. These phenomena may be mainly 

 accounted for, in the case of Lapland, by the inlluence of the gulf stream which washes 

 its shores and raises the temperature of the western winds which blow over its plains ; 

 and in the case of Asia, by the great southern bend of the isothermal lines which cross the 

 continent, and the consequent excessively low temperature and small amount of pre- 

 cipitation. 



Further, J. D. Hooker informs us that an examination of the course of the annual and 

 monthly isothermal lines reveals the fact, that the relation existing between the average 

 temperature and the vegetation of the areas through which the lines pass, is only a general 

 one, illustrated on the one hand by the richness of the Lapland flora and the northern 

 bend of the isothermals, and on the other by the extreme scantiness of the Siberian flora 

 and the great southern inclination of these lines But even this relation seems to fail 

 when we compare Eastern Arctic America with G-reenland. The annual isotherm of 32° 

 F. descends as far south in the longitude of Hudson Bay as the 50th parallel, and then 

 bends away northward, crossing the southern extremity of G-reenland and passing on 

 north of Iceland, and yet Eastern Arctic America is richer in species than Grreeuland and 

 Iceland. 



The theory, originally enunciated by Forbes, more fully developed by Darwin, 

 adopted and illustrated by Hooker, and perfected by CroU, that previous to the Glacial age 

 a homogeneous flora covered the Arctic regions, and during the cold was driven south in 

 every longitude and, mingling with the flora of other areas, became modified by the struggle 

 for existence with the native species of the invaded latitudes, and that the survivors fol- 

 lowed the retreating ice to their original homes in the north, may be accepted as a general 



