THE GARDENERS' CHRONICLE OF AMERICA 
351 
withdrawn from its pocket by the head of a departing' 
butterfly. 
The second sketch shows a similar section of another 
flower where we see that the stigmatic surface is so low 
first (lower its slender stalk withers, its head droops for- 
ward and, carried to the second flower, it unfailingly 
strikes the stigmatic surface in the roof of the honey well, 
and the flower is fertilized. 
Tick Trefoil {Desmo&ium nudWorum). 
and so far back that the pollen club, erect upon the but- The third sketch shows the front view of the flower 
terfly's head, could never strike the mark. But nature so of the orchis with pollen clubs lying in their pockets 
plans that as soon as the pollen club is withdrawn from the above the honey well. 
Some Peculiarities of Plant Life 
W. C. Egan, Illinois 
I HAVE often wondered if plants were endowed 
with instinct. We all know that instinct is an 
impulse to act without a preliminary reasoning 
as to why the act should be performed. Plants often 
act in this manner and why should we not attribute it 
to instinct ? 
Darwin experimented with a vine grown in a pot. 
The vine had reached some six inches higher than a 
stake which supported it and was wandering aim- 
lessly around. He placed the pot within a few inches 
of a string fastened perpendicularly reaching higher 
than the vine. The following morning he found that 
it had reached over and entwined itself around the 
string. He unloosened it and placed it at the opposite 
side and the vine soon found it as before. How did 
the vine know where to find the string? Was it in- 
stinct ? 
Why do the runners of a strawberry plant extend 
quite a distance from its parent before they root at 
the tips unless it is to get into unoccupied soil and 
thus have ample food? Something akin to instinct 
must prompt it. 
Some years ago I had a Paulownia imperialis in an 
individual hole some eight feet away from a well en- 
riched flower bed. It remained there probably five 
years when I took it up. I had noticed a mass of 
feeding roots in the flower bed and presumed it came 
from the Paulownia, but as the roots of a tree in an 
open situation generally radiate from the main trunk 
like the spokes of a wheel and extend as far as the 
branches overhead, it would make the root system of 
this tree fully sixteen feet in diameter, entirely too 
large for the'size of this tree. The puzzle was soon 
solved. The hole in which the tree was planted was 
about three feet in diameter, hardly large enough for a 
single perennial, but I did not know better then and 
none of the roots reached the outer edge when plant- 
ed, nor were any of them more than three-quarters of 
an inch in diameter. When I took up the tree I 
found that none of the roots but one had gone be- 
yond the original hole more than five or six inches 
and had not increased in size to more than an 
inch thick. The one exception was a root originally 
pointing towards the mine of rich food, the flower 
bed, which had run directly towards it and upon 
reaching its borders had spread its fan-shaped system 
of feeding roots all through the bed. This root had 
forced itself through six and a half feet of hard clay 
loam in order to reach a rich foraging ground and 
was as thick as my arm at its base. The root had to 
enlarge its carrying capacity in order to convey the 
great supply of food its feeding roots were giving it. 
It was in fact the main source of food. How did this 
tree know of that mine of food eight feet away and 
what caused it to push forward to it? It must have 
stinted the downward flow of sap to the other roots 
and pushed this one on rapidly so as to reach the 
feeding ground. 
A plant bent over permanently will soon turn up its 
tips and side branches. It seems to know that the full 
effect of sunlight on all its foliage is necessary in 
order to prepare its sap for assimilation. How does 
it know it, and knowing it what prompts it to act? 
It may be called a law of nature. So it is. Instinct is 
one of the laws of nature. The law of nature causes a 
duckling to take to the water. We call it instinct. 
I mentioned the fact that the Paulownia had forced 
one root over six feet through a hard clay loam, en- 
countering hard obstacles such as stones, etc. We 
marvel at this when we consider that the terminal 
point of a root is slender and pliable. The feeding 
roots are mainly of annual duration and are slim and 
hairlike. The roots we see when a tree is taken up 
are mainly bark-covered channels through which the 
sap gathered by the feeding roots is conveyed to the 
tree. The extended growth of a branch or root is 
caused by the growth — by multiplication — of the cel- 
lular tissues. New cells are produced and the new 
growth thus extended. The power pushing this new 
growth forward is mysterious but effective. It is said 
that a mushroom that may be crushed under one's 
foot has a power during its growth to lift a flagstone. 
This mysterious growing power is constantly pushing 
the tips of the root through the soil, but so slowly and 
