440 THE CAUSES OF THE XI 
destroyed as are born; that is the inevitable ulti- 
mate result of the rate of production. Now, what 
is the result of all this? I have said that there 
are forty-nine struggling against every one; and 
it amounts to this, that the smallest possible start 
given to any one seed may give it an advantage 
which will enable it to get ahead of all the others ; 
anything that will enable any one of these seeds to 
germinate six hours before any of the others will, 
other things being alike, enable it to choke them 
out altogether. I have shown you that there is 
no particular in which plants will not vary from 
each other; it is quite possible that one of our 
imaginary plants may vary in such a character as 
the thickness of the integument of its seeds; it 
might happen that one of the plants might pro- 
duce seeds having a thinner integument, and that 
would enable the seeds of that plant to germinate 
a little quicker than those of any of the others, and 
those seeds would most inevitably extinguish the 
forty-nine times as many that were struggling 
with them. 
I have put it in this way, but you see the practi- 
cal result of the process is the same as if some 
person had nurtured the one and destroyed the 
other seeds. It doesnot matter how the variation 
is produced, so long as it is once allowed to occur. 
The variation in the plant once fairly started tends 
to become hereditary and reproduce itself; the 
seeds would spread themselves in the same way 
