1 46 BOTANICAL GAZETTE. 



erations of human life. The forest fire, then, which destroyed the 

 pine, destroyed as well the capacity of the land to produce a similar 

 crop for a period of from 50 to 100 years. The damage inflicted 

 upon the land is, of course, not irreparable in a climate like that 

 of New-England, where the annual rainfall is sufficient always to 

 insure a growth of trees of some sort upon undisturbed ground, and 

 sooner or later in the ordinary workings of Nature's laws forests 

 will succeed each other here; but in some parts of the country 

 where the rain fall is so slight that there is a constant and severe 

 struggle between the forest and the plain and where trees under 

 the most favorable conditions barely exist, a fire not only kills the 

 forest but it makes any future growth of trees impossible. We in 

 New-England are more fortunate; and it is entirely within our 

 power to regulate the composition of our forests and maintain a 

 proper proportion between forest areas and farming land. 



The Orgin of our Vernal Flora— The following remarks 

 on this interesting subject have just appeared in "Nature," by' Dr. 

 J. E. Taylor. It is usual to assign an Arctic origin to our mountain 

 flora, and the floral comparisons and statistics fcfully bear out this 

 brilliant generalization. It is formulated that height above the 

 sea-level is climatally equivalent to northern latitude. This is 

 an assumption that flowering plants are largely conditioned by 

 heat. Thus latitude and oreographical habitats are more or less 

 equal. 



Might I introduce another element into this question ? See- 

 ing- that temperature is so largely influential in explaining the dis- 

 tribution of flowering plants, it occurs to me that not only may 

 height above the sea-level answer to northern distribution, but 

 seasonal occurrence as well. 



All botanists must have been struck by the fact that- the earli- 

 est plants to bloom among our vernal flora are genera peculiarly 

 Alpine. In some instances (as with Chrysosplenium oppositifolium 

 and C. aUernifolium) the species are identical. These latter'plants 

 blossom with us in March or April; within the Arctic circle not un- 

 til June or July, and even so late as August. Thus, with them, 

 seasonal blossoming is equivalent to northern latitude, as re- 

 gards the thermal conditions under which they flower. The gener- 

 ic names of all our early flowering plants are those pre-einintntfy 

 Alpine aud Arctic in their distribution — Potentilla, Stellaria, Saxi- 

 fraga, Clirysospienium, Draba, Ranunculus, Cardamine, Alsine, &c. 

 I contend, therefore, that our vernal flora is explained by the fact 

 that their seasonal occurrence, as regards temperature, is equivalent 

 both to height above sea-level and northern latitude. In every 

 instance it will be found that the blossoming of the species of the 

 above genera necessarily takes place, in Great Britain, two or three 

 months earlier than within the polar circle. May we not there- 

 fore contend that we owe our English vernal flora to the same 

 causes as distributed our English iUpine plants; and that_they are 



