Choosing the Varieties. 227 
4. Choose with reference to the local environment. 
One must consider the adaptation of the variety to 
his particular climate, to the probable length of his 
season, to his distance from market, 
and to his system of husbandry. 
The adaptation of varieties to soils 
is an important consideration, and 
one which demands closer attention 
as cultivation becomes more intense 
and perfect. As a rule, the finer 
the variety in quality, the less able 
it is to thrive equally well under 
diverse ‘methods of treatment. It 
is partly for this reason that des- 
sert fruits are commonly regarded 
as unreliable and difficult to grow. Fig. 22. Strawberry 
One can scarcely hope for success in S°*e'S modified by 
the best horticulture unless he gives 
particular study to the adaptations of species and 
varieties to soils. 
5. Choose with reference to inter-pollination. It is 
known that some varieties of fruits are self-sterile,— 
that is, they are not fertile with themselves. This 
sterility may be due, as in the ease of the straw- 
berry, to imperfect (or unisexual) flowers, or, more 
commonly, to pollen which is impotent upon the 
pistils of the same flower.* This infertility or self- 
sterility is largely a varietal characteristic, yet it is 
no doubt greatly modified by seasonal and environ- 
*For a discussion of the philosophy of this self-sterility, see the essay on 
“Sex in Fruits,” in “Survival of the Unlike,” p. 347. 
