448 STERILITY. 



The buds of apples are covered with thick scales, 

 and these are lined with pubescence, which make 

 them still less conductors of heat ; and therefore 

 these are not so easily affected by the warm days in 

 severely cold seasons. But the peach and the 

 cherry are natives of a warmer climate, where, as 

 such, a protection is unnecessary. Hence nature did 

 not give them these peculiar properties. As species 

 never lose their specific character, it is impossible 

 to raise a peach which shall have scales thick 

 enough, or be coated with sufficient hair, to defend 

 them from these vicissitudes. 



After an extreme of cold has just passed, and it 

 is again comparatively warm so that decay can go 

 on, a cultivator can easily determine whether the 

 vitality of the buds is destroyed by cutting one 

 smoothly in halves, and seeing whether there are 

 any dark spots in the centre, since these denote the 

 death of the embryo. 



" One of the ordinary causes of sterility," says 

 Dr. Berkeley, " whether permanent or temporary, 

 is the hypertrophy or absence of some particular part 

 of the plant. The nutriment which should have 

 been employed in the formation and perfection of 

 the organs of fructification is thus diverted to some 

 other purpose. These organs may be apparently 

 perfect, and yet no impregnation take place, even 

 though the pollen grains may germinate. It is 

 possible that, in such cases, there is some deficiency 



