462 KINSHIP AND ADAPTATION 
plants in their responses to outside influence are sometimes 
capable of acting in one way rather than in another way which 
is equally possible, then all that is essential to what is here 
meant by choice will be conceded, and he may be willing to 
entertain an hypothesis which squares well with what we 
know of all living things. In such a hypothetical view we 
need not suppose that every action of every creature is an 
act of will. Many of our own acts are, as we say, mechanical 
or habitual. We may well suppose that most of the behavior 
of lower organisms, including the behavior of growth, is of 
this sort. Nor do we need to suppose that consciousness 
more than very remotely like our own accompanies any of 
the actions or reactions of plants. All the hypothesis requires 
is that sometimes, even with dimmest consciousness, any 
organism may be free to choose at a critical moment between 
alternatives profoundly affecting its constitution. 
By way of example let us suppose the seeds of a primitive 
buttercup to be carried near the seashore and to begin to 
sprout. Such plants are not accustomed to so much salt as 
would then be in contact with their roots. Here is a change 
of condition, favorable, as we have seen, to the occurrence 
of mutations. It has been found by experiment that plants 
of the same kind placed under the same conditions will absorb 
different amounts of the same substance, as, for instance, 
common salt. Thus of several seedlings the same in kind 
and age, growing with their roots in the same salt solution, 
some will absorb a larger percentage of the salt than others, 
and, indeed, may be poisoned while others survive. Some- 
times even the same individual may respond differently at 
different times. Now, what we may suppose to happen, 
according to our hypothesis, in the case of the buttercup 
seedlings is that some of them might choose to keep out so 
much of the salt that they could not get water enough to 
live; others might let in so much salt as to be poisoned by it; 
while still others might let in just enough salt to permit their 
having sufficient water, but not so much salt as would kill 
them. The survivors, as a consequence of their choice, 
would have their sap saltish and thus every organ would be 
affected in an unwonted way. Their seeds would start with 
