124 DOMESTICATED ANIMALS AND PLANTS 
It will be found that the characteristic thing which normally 
happens is this: one of the little particles of yellow dust drops 
upon the sticky tip of the silk, adheres, and begins at once to 
grow, not upward like a seed, but down the silk throughout its 
entire length to the ovule at its base. 
Now the pollen grain is itself, like the ovule, a sex cell, though 
a very small one, with its nucleus and its surrounding protoplasm. 
The latter is consumed during the progress down the silk, but 
the nucleus descends until it reaches and unites with the nucleus 
of the ovule. 
Fertilization. This is fertilization, after which the ovule, 
which would otherwise wither away, is capable of developing 
into a kernel of corn, which will be pure or mixed as to its unit 
characters according as the two nuclei that blended for its 
development were of the same or of different parentage. 
~ The unit characters of the parents are undoubtedly contained 
in the two nuclei, and these are what decide the character of the 
offspring. It seems inconceivable that so small a bit of matter 
as a pollen grain or the nucleus of the ovule, each far smaller 
than the head of a pin, can carry so many and such profound 
potentialities ; but the character of these two nuclei alone deter- 
mine whether the kernel shall be white, yellow, or mixed, sweet, 
field, or pop corn. If both are from white parents, then the ker- 
nel will be white and will transmit white characters only ; but if 
one be from a white parent and the other from a yellow, then 
the kernel will be mixed and will in its turn transmit both white 
and yellow characters. Corresponding results will follow if one 
should be field or pop corn and the other should be sweet corn. 
Moreover, this kernel, whatever its parentage, may afterward 
“grow” and in its turn give rise to an entire new corn plant, 
kinds of protoplasm, each with its own particular function to discharge. These 
cells lie closely packed together, like rubber bags filled with thickened water, 
and near the center of each is its “ nucleus,” which is its densest portion and 
the part which takes the initiative in cell division and growth. If it happens 
to be a sex cell, the nucleus is the repository of the hereditary matter and the 
seat of transmission. 
