IAS: 
reason given above, that it is better for the plant to become grad- 
ually accustomed to the cold. 
As regards the amount of snow on the ground in December, it 
will be seen from the table that ten inches fell on the 26th, which 
had melted to 6.6 inches by the 3lst. The amount of snow cover 
during these cold spells is an important and decisive factor in the 
amount of winter injury sustained by low-growing plants such 
as the Heaths. Snow protects the parts that it covers both from 
extreme cold and from the drying effects of the winds. Further- 
more, it protects the roots of the taller plants. Dr. Alfred Gunder- 
sen, Curator of Plants at the Garden, tells us that in his native 
home in Norway each spring the low-growing woody plants were 
often found killed down to a definite line. This was the snow 
line. 
In the case of the Swiss Heath (Lrica carnea), which now for 
twelve years has done yeoman service through all the winter, often 
blooming on a warm day even in January, this blanket of snow 
probably saved its life. For we find that although the upper 
parts are killed, there are many sound shoots close to the ground. 
The other extreme cold period, as shown in the table, was in 
February, 1934. The mercury on February 9 stood at — 14° im 
—the lowest that the weather bureau in New York City has ever 
recorded. But the figures we have reproduced for a few days in 
February do not tell the entire story, for the weather continued 
extremely cold throughout the month, with a minimum of 3° above 
zero on the 14th, 6° above on the 24th, 7° above on the 28th, and 
many other days on which the minimum was not far above these 
figures. The mean minimum for the whole month was 10.8° and 
the mean maximum 28.9°, as against a normal minimum of 24.2 Zo 
and a normal maximum of 38.4°. It was an extremely cold 
month as a whole: on only ten days of the month did the tempera- 
ture rise above the freezing point, and on only four days above 
0°. As regards the snow cover, however, we were again for- 
tunate, for during the coldest period, as shown in the table, there 
was a considerable blanket of snow on the ground. For a few 
days, namely, from the 12th to the 17th inclusive, this was reduced 
to from 214 inches to half an inch on the 18th; but snowfalls on 
the 19th, 20th, 25th, and 26th replenished the supply, so that at 
