THE IMMOBILE SEED 51 
cold which would be fatal to the parent; it can be 
drowned, or scorched, or dashed about, or in many 
cases eaten by animals without injury; it can lie buried 
in the soil for a long period of years, yet if turned up 
again and placed within reach of the requisite amount 
of air and heat, will spring up vigorously. 
As a matter of fact, investigation soon shows that 
absence of special devices for dispersal provides no 
measure of the breadth of a plant’s distribution, nor 
is profuse seed-production necessarily related to 
abundance of offspring. Many factors come into 
play, and conclusions of this obvious kind will 
generally only lead us astray. But that does not 
render the study of each one of the factors less 
interesting. 
This matter of seed-dispersal is of prime importance 
in our study of familiar British plantscapes, for our 
vegetation is the expression of the past and present 
efficiency of its particular rdle in the ever-changing 
drama of Nature. We shall do well to spend a little 
time in considering it. 
First of all, as to the nature of the seeds with which 
we have to deal. These are, as already pointed out, 
young plants, already a long way advanced from the 
ege stage, neatly tucked up and enclosed, in most 
cases along with a supply of food material, in a tight, 
strong skin, which is mostly of a particularly impervious 
character, protecting the young plant from injury by 
bruising, from attacks of small animal enemies, from 
extremes of heat and cold, of moisture and dryness. 
The young plant, too, is in a peculiarly resistant phy- 
siological condition. For instance, its breathing—or 
absorption of oxygen—is exceedingly slow, and it is 
