THE AMERICAN BOTANIST, 
113 
stigmatic disc which we see in the centre of the flower, and 
that yet, after some preliminary struggle for precedence, 
only an equal number of tubes must have traveled down- 
wards and found their way unerringly to perhaps every 
seed in the capsule, we cannot fail to be struck with 
w^onder and admiration at the arrangement w^hich can 
admit ol all this without a shadow of confusion. 
This, however, is a minor wonder as compared with 
the pollen grain itself. Their number, as we have seen, is 
simply enormous in man3^ instances, and very large in all, 
and yet in every one, tiny as they ma}^ be, there is bound 
up not merely the potencies of the entire parental plant, 
but also of its ancestors, and if, as well may be, that plant 
has been cross bred at any time, two or more sets of 
ancestral potencies will be lying latent, and be capable of 
asserting themselves when fertilization is completed. 
Notwithstanding this innate complexity, the bulk of the 
grain is, as we have seen, devoted merely to tube forma- 
tion, and hence, at the time of fertilization, nothing is left 
but a single microscopic cell, which it has been the function 
of the tube to convey. 
This cell, the biologist will tell us, is really only half a 
cell as regards the normal cell contents, and the embryo 
cell in the seed-vessel is similarly halved. It is this prelim- 
inary halving which renders fertilization necessary, and 
the act of fertilization consists in the union of the two 
halves into one complete cell, which is thus rendered cap- 
able of growing, dividing, and multiplying, and building 
up first a seed and then a plant. Inasmuch as the half 
cells of the embryo seed are equally endowed with parental 
and ancestral potencies, the perfected seed contains both 
sets, and its subsequent development into a plant is deter- 
by some sort of subtle adjustment, which in the case of 
cross-bred plants, leads to immense variety, and yields our 
selective cultivators many of their richest prizes. — Indian 
Planting and Gardening. 
