120 BOTANICAL GAZETTE [FEBRUARY 
amount of food manufactured then is much less than at higher tem- 
peratures. Light is the least variable of all the climatic elements. 
Possibly for a given altitude and a given latitude the variability is 
not great enough to have much influence on the kind of vegetation. 
However, the sunshine data may prove of importance in comparison 
with other regions. In the table below the mean possible hours of 
sunshine, which would be the same for a given latitude, and the 
mean actual hours are given. The observations cover a period of 
short duration. 
TABLE V. 
JANUARY FEBRUARY Marcu APRIL 
Poss. Act. Poss. Act. Poss. Act. Poss. Act. 
Mahseell. 25ers 276.2 88.2 286.8 111.8 | 370.1 180.7 410.4 | 240.2 
Escanaba 283.1 85.3 290.4 120.5 370.3 129.8 407.0 178.4 
Seattle 276.2 66 286.8 | 103.8 | 370.1 168.6 | 410.4 | 205.2 
May JUNE Juiy AuGUST 
Poss. Act. Poss. Act. Poss. Act. Poss. Act- 
pe! eee eee 471.3 | 231.4 | 479.8 | 279.6] 483.2 364.4 | 442.5 | 269.6 
De oP na eee | 464.3 | 163.8 | 473.7 |] 238.7 | 475.7 | 211.5 | 437-6 | 230-5 
Seattle 471.3 | 226.9 | 479.8 | 248.5 | 483.2 | 301.7 | 442.5 | 257-5 
—— 
SEPTEMBER OcTOBER NoveMBER | DECEMBER ANNUAL 
Poss. | Act. | Poss. | Act. | Poss. | Act. | Poss. | Act. | Poss. | Act 
Kalispell — 202.5] 335.8| 174.6] 278.0] 73 | 262.1] 49 |4473-7|2262-9 
PMMA, cial) ptel eae Bele al 376.1] 149.1) 338.5] 148.8] 284.1] 52.9] 269.6) 61.4) ..-- |1727-7 
Seattle. 377-5| 186 335.8] 110 278 | 40.6] 262.1] 45 |4473-7 1959-6 
ae 
In his classification of climatic formations, SCHIMPER (ppP- 550- 
565) does not recognize a distinct formation for the coniferous forest, 
placing it in what he calls the summer-green forest (deciduous). 
There is little doubt that he is right so far as the eastern part of the 
United States south of the latitude of Lake Superior is concerned. 
Here, as shown by Cow tes (/. c.) and the writer (J. c.), the conifer- 
