26 
NORMAN TAYLOR 
comparison of the figures thus obtained. The following table gives 
a few of the percentages as determined by Raunkiaer for widely 
separated areas. The percentages of the normal spectrum are given 
for comparison. 
Percentages of Growth Forms in Biological Spectra, after Raunkaier 
Type of Growth-form 
MG and 
MS 
MC 
N 
CH 
H 
G 
HH 
T 
Normal spectrum 
6 
17 
20 
9 
27 
3 
I 
13 
Baffin's Land 
I 
30 
51 
13 
3 
2 
Georgia 
5 
7 
II 
4 
55 
4 
6 
8 
Denmark 
I 
3 
3 
3 
50 
II 
II 
18 
Seychelles 
10 
24 
6 
12 
3 
2 
16 
Libyan Desert 
3 
9 
21 
20 
4 
I 
42 
These figures give some idea of the variation of climate implied 
by the different growth-forms predominating in the different areas. 
They also make more cogent the terms phanerophytic, hemicrypto- 
phytic and chamaephytic as applied to climate. 
Raunkiaer has indicated three types of climate, as shown by his 
study of growth-forms, namely a tropical area, an area of decreasing 
warmth correlated with an increasing difference between winter 
and summer temperatures and with a favorable distribution of preci- 
pitation, and lastly a region with decidedly decreasing temperature, 
or also, very commonly, with an unfavorable distribution of precipi- 
tation, such as in deserts. The tropics are typical of the first of these 
conditions, the eastern sides of North America and Asia are typical 
of the second, and the arctic region and some deserts are characteristic 
of the third type of climate, which may be seen also in our own South- 
west. Many refinements of these rather gross outlines of climate 
have been worked out, based on the so-called biochore, which is a line 
with the same percentages of a definite growth-form, as found in 
different parts of the continent. Such a study of the flora of North 
America would be extremely interesting. It can be rightly based 
only on complete percentages of growth-forms for different parts 
of the country, and it is with the idea of supplying this for the local 
flora area that the present paper has been written. 
In attempting to apply Raunkiaer's principles described above 
and to get the biological spectrum of the flora near New York, I have 
thrown out of the calculation all the 615 species of introduced weeds, 
