216 
Incidentally the seedlings were carefully studied, more especially as 
to their resistance to temperature and moisture changes, in a less degree 
as to the form and arrangement of their earlier foliage leaves, since these, 
perhaps, in many cases may be regarded as representing inherited forms, 
while the later leaves stand for adaptive responses to light intensity and 
other ecologic factors. The results of the observations upon this point 
have not been sufficiently considered to warrant their presentation at this 
time, except in a few instances which indicate that many suggestions as 
to relationships would probably be one of the results of such a study. 
It will be recalled, when we consider our native plants, that the in- 
crease in numbers and the consequent amount of territory occupied by 
any specific form bears no direct relation to the number of seeds it may 
produce. Indeed, the production by a given plant of a vast number of 
seeds, with adaptations for a wide dispersal, should, perhaps, be taken 
as an index of the intensity of its struggle for existence, and stand as a 
sure sign that, save through some change in ecological factors, the form 
will do little more than maintain itself in nature. 
This view, which it will be remembered was advanced by Weismann, 
is being confirmed by observations upon plants. The setting of a large 
number of seeds stands not as the sign of a rapid increase in numbers 
of the form, but rather the reverse. An example or two may emphasize 
the statement. 
The common nightshade (Solanum nigrum) is a plant with which all 
are familiar. Where it obtains a foothold it usually holds its own, but 
rarely becomes dominant or so increases in number from year to year as 
to attract attention. From one of these plants which bore forty-three 
berries and was still flowering, I took three berries and planted them after 
having broken the outer walls. One hundred forty-two seedlings appeared. 
Surprised at the result I planted three other seedlings similarly treated, 
being especially careful to eliminate error. In this case one hundred eighty- 
seven seedlings appeared. This would indicate that each berry contained 
on an average at least fifty viable seeds, and as there were over forty 
berries, the potential product from that single plant was over two thou- 
sand plants. 
From the ordinary Scrophularia, germination percentages ran from 
fifty-six to seventy in the favorable conditions of the laboratory, indicat- 
ing an almost incredible possible increase from a single plant. Yet every 
