54 College of Forestry 
which of course for the mountain summit would be extreme. 
Again the lowest winter temperatures, the duration of zero 
or below zero temperatures and so on. 
On Staten island are found such Austral plants as sweet 
gum, persimmon, mistletoe, willow oak, ete. On Mount 
Marcy, arctic species, such as Diapensia lapponica, Rhodo- 
dendron lapponicum and a score of other species whose dis- 
tribution is throughout the arctic regions of the three 
northern continents extending southwar d only on high moun- 
tains. This is much the sort of difference that one Soll get 
as between southern Illinois and Hudson bay. It supports 
the suggestion that within New York State there may be 
recognized a right wide range of floral provinces. But I wish 
to eaution the reader against accepting without qualification 
the alleged facts of temperature effect as determined by 
elevation. Many of the phenomena of distribution will be 
found correlated with soil conditions, slope and exposure, 
local air drainage, etc., so that in reality the local edaphic 
conditions must be known. 
Effects of Elevation on Zonal Relations as Shown by 
Transects of the State. 
A very instructive and in general a very effective study 
of the facts of plant distribution on a panoramic scale, as it 
were, may be made from the car window * while traversing 
the State on the various railway lines. After you have 
gotten the habit well formed and have learned to recognize 
a fairly wide range of species at a distant and rapidly 
passing glance, the landsc: ape becomes a particularly enter- 
taining ‘‘ movie.” 
Transect from the Lower Hudson to Rouse’s Point. 
Thus in traveling from New York City to Rouse’s Point 
you make a complete north-south transect at very slight eleva- 
tions along the Hudson-Champlain Valley. Beginning with 
1 We are indebted to Dr. R. M. Harper of College Point, L. I., for 
vigorous support of projects connected with the study of the geographi- 
cal distribution of plants. The “car window” method of studying 
plant distribution has been used and recommended by him as a valu- 
able adjunct to more detailed studies. 
