A Aloimtain Tulip. 195 



the beautiful tumbled range of the White Mountains. 

 On and near its summit a small community of butter- 

 flies belonging to an old Glacial and Arctic species 

 still lingers over a very small area, where it has held its 

 own for the eighty thousand years that have elapsed 

 since the termination of the great ice age. The actual 

 summit of the mountain rises to a height of 6,293 ^^^t ; 

 and the butterflies do not range lower than the five 

 thousand feet line— as though they were confined on 

 Snowdon to a district between the Ordnance cairn and 

 the level of the little slumbering tarn of Glasllyn. 

 Again, from Mount Washington to Long's Peak in 

 Colorado, the distance amounts to 1,800 miles ; while 

 from the White Mountains to Hopedale in Labrador, 

 where the same butterflies first reappear, makes a bee- 

 line of fully a thousand miles. In the intervening 

 districts there are no insects of the same species. 

 Hence we must conclude that the few butterflies left 

 behind by the retreating main-guard of their race on 

 that one New Hampshire peak have gone on for 

 thousands and thousands of years, producing eggs 

 and growing from caterpillars into full-fledged insects, 

 without once effecting a cross with the remainder of 

 their congeners among the snows of the Rocky Moun- 

 tains or in the chilly plains of sub-Arctic America. 

 So far as they themselves know, they are the ^ 



