Development of the Vegetation of New York State 37 
Then the sperm could reach the egg through the pollen-tube. 
Now, in angiosperms, provision for the nurture and protec- 
tion of the embryo went a step further in the attainment of an 
enclosed ovary (hence the term angiosperm), and then fol- 
lowed gradually the elaboration of accessory structures in 
connection with the stamens and pistils: a protective calyx; 
a colored calyx; a differentiation of protective members 
(calyx) and attractive members (corolla) ; secretion of spe- 
cific odors and of nectar accompanied by special glands, con- 
tainers (nectaries) and nectar guides; special forms of flow- 
ers, special times and manner of opening of the flower and 
so on through the whole significant field of floral adaptation 
in which the reproduction of a new individual (except 
through vegetative propagation) centers in the act of pollina- 
tion and subsequent fertilization of the egg and thereby opens 
the way to great vigor and variability of progeny through 
crossing, hybridizing and so on. 
It is not to be inferred that these advances took place in 
the Tertiary simply, for numbers of genera from the later 
Cretaceous period show advanced floral structures. But the 
presence of such qualities together with a combination of 
specially stimulating environmental factors, climatic, eda- 
phic, biologic (insect pollination for example), could be 
made to account for the apparent energy and rapidity with 
which angiosperms burst into dominance in the Tertiary. 
Intensified Relationship Between Animals and Plants. 
Another important item of geological teaching is that “ the 
Cretaceous revolution in vegetation was not only great as a 
phytological event, but was at least susceptible of profound 
influence on zodlogical evolution, for it brought in new and 
richer supplies of food in the form of seeds, fruits and fodder. 
“* * * The introduction therefore of dicotyledons, the 
great bearers of fruits and nuts, and of the monocotyledons, 
the greatest of grain and fodder producers, was the ground 
work for a profound evolution of herbivorous and frugivor- 
ous land animals” (Chamberlin and Salisbury III, pages 
