DARWINISM 515 
kill the less vigorous, though fully grown plants; thus out 
of 20 species growing on a little plot of mown turf (3 feet 
by 4) nine species perished, from the other species being 
allowed to grow up freely." 
"Struggle for Existence" Used in a Large Sense. "I 
should premise," said Darwin, "that I use this term in a 
large and metaphorical sense including dependence of one 
being on another, and including (which is more important) 
not only the life of the individual, but success in leaving 
progeny. Two canine animals, in a time of dearth, may 
be truly said to struggle with each other which shall get 
food and live. But a plant on the edge of a desert is said 
to struggle for life against the drought, though more 
properly it should be said to be dependent on the moisture. 
A plant which annually produces a thousand seeds, of 
which only one on an average comes to maturity, may be 
more truly said to struggle with the plants of the same and 
other kinds which already clothe the ground. The mistle- 
toe is dependent on the apple and a few other trees, but 
can only in a far-fetched sense be said to struggle with 
these trees, for, if too many of these parasites grow on the 
same tree, it languishes and dies. But several seedling 
mistletoes, growing close together on the same branch, may 
more truly be said to struggle with each other. As the 
mistletoe is disseminated by birds, its existence depends 
on them; and it may metamorphically be said to struggle 
with other fruit-bearing plants, in tempting the birds to 
devour and thus disseminate its seeds. In these several 
senses, which pass into each other, I use for convenience 
sake the general term of Struggle for Existence." 
5. Survival of the Fittest. In this struggle for existence 
only those best suited to their environment will survive. 
