CELL-NUCLEUS—FERTILISATION 249 
our attention on the manifold variety ex- 
hibited by plants, the adaptedness of species 
to their environment is always one of the 
most striking of their many qualities. But, 
as we have seen, this adaptedness is intrinsic- 
ally the result of the inner constitution of 
the plant, which impels it of necessity to 
develop in this or that particular manner. 
Only those plants whose constitutions are such 
as to cause their development to be adapted 
to a given environment can flourish under the 
particular conditions imposed by it. 
Adaptedness is often achieved in an indirect 
fashion, but it must be susceptible of realisa- 
tion in some way or another if the individual 
is to survive. 
Every species, just as every individual of 
the species, has to face its critical problems. 
And the problems of the species are really 
the same, though sometimes disguised under 
different forms, as those which confront the 
individual. The race problems are solved by 
the individuals, often in a wonderful way. 
Thus many tolerably heavy fruits are dis- 
persed by a wing-like outgrowth which delays 
their descent to the ground. But at an 
earlier stage this wing-like outgrowth is 
generally green, and so may well have helped 
in the nutritive processes. We can state with 
confidence that it was not developed 7a order 
to aid in the dispersal of the fruit, but that it 
arose as the result of far backward-reaching 
correlations of ultimate structure and chemical 
