34 
AMERICAN JOURNAL OF BOTANY 
[Vol. 9 
disappeared from any of the recorded stations. Another question of equal 
interest is whether the number of individuals in the various colonies is 
dwindling at the present time and thus forecasting the disappearance of 
the species in this area. To determine this latter point a detailed study of 
one particular substation, that in Jamesville Woods {H, fig. 2), has been 
made. This locality was selected for study because it is the most accessible 
area containing more than one colony. 
H. The Jamesville Woods Substation. The special study of this sub- 
station was begun in the autumn of 1916. The entire area is dissected by 
a maze of ravines and plunge basins in which the colonies of Scolopendrium 
occur. A sketch map of the region was made, and the locations of the 
six colonies found were indicated on this. Each colon}/ was then examined 
in detail, and a careful census of the plants was made. To accomplish 
this, each area was divided into strips from ten to twenty feet in width and 
extending from the bottom to the top of the slope. These strips were 
then examined in order, beginning each time at the foot of the slope; the 
plants found were recorded as mature plants, young plants, or groups of 
prothallia, as already described. The census of selected strips was checked 
by recounts, and in one instance an entire colony was recounted. 
In the autumn of 1920, a second census of the colonies was made by 
the use of the same methods. The results of the two counts are given in 
table I. 
Table i. Jamesville Woods Substation 
Number of 
Number of 
Number of Groups of 
Colony 
Mature Plants 
Young Plants 
Prothallia and Sporelings 
1916 
1920 
1916 
1920 
1916 
1920 
I 
159 
197 
56 
85 
38 
60 
II 
100 
115 
36 
17 
23 
Ill 
17 
8 
5 
7 
3 
IV 
119 
206 
17 
52 
V 
29 
20 
9 
4 
6 
2 
VI 
136 
92 
86 
72 
35 
48 
Totals 
569 
638 
235 
291 
120 
18S 
Increase 
69 
56 
68 
Increase percent . . 
12.1 
23.8 
56.6 
As shown by the table, the number of mature plants in the substation 
increased 12. i percent in four years. The increase in young plants and 
groups of prothallia has been even more rapid, and is interpreted to mean 
that the increase in number of mature plants may be expected to continue 
in the immediate future. 
This increase, however, is not common to all colonies of the substation, 
colonies III, V, and VI showing a decrease instead. Colonies III and V 
