288 NEW VORK STATE MUSEUM 
Among the northern species that find their southern limit somewhere 
in this zone may be mentioned: 
Cypripedium reginae showy ladies’ slipper 
Cypripedium hirsutum large yellow ladies’ slipper 
Cypripedium parvifiorum small yellow ladies’ slipper 
Arethusa bulbosa arethusa 
Taxus minor‘ American yew 
Thiga occidentalis white cedar 
Tsuga canadensis hemlock 
Corema conrad - Conrad’s broom crowberry 
Populus grandidentata large-toothed aspen 
Betula lutea yellow birch 
Menyanthes trifoliata buckbean 
Diervilla dervilla bush honeysuckle 
Comarum palustre purple or marsh cinquefoil 
Oxalis acetosella white or true wood-sorrel 
Plant life is active in this zone during two thirds of the year, and it is 
consequently the most northerly life area of any real agricultural impor- 
tance. ‘‘ Many vegetables. the sugar beet, chicory, oats and numerous 
varieties of plums, cherries, pears, grapes, white potatoes and cereals 
attain their highest perfection” (Merriam, ’98, p. 20). ‘The principal 
crops of the Atlantic division of the transition zone (* Alleghanian faunal 
area’) tabulated by Merriam (BS, Pp. 20-24) ane: 
wheat (7 varieties) currants (11 varieties) 
barley black currants (4 varieties) 
rye apples (go varieties) 
corn (8 varieties) crab apples (16 varieties) 
sorghum pears (37 varieties) 
oats (5 varieties) quinces 
sugar beet cherries (31 varieties) 
buckwheat plums (41 varieties) 
hops grapes (17 varieties) 
white potatoes strawberries (13 varieties) 
flax 
There can be little doubt that the area occupied by the transition 
zone in New York has been very materially increased by the clearing 
away of the forests. The process of local extension of the transition 
zone may be observed in any region where Canadian forests are in 
process ol clearing from the southern side. As the cool forest cover- 
