1892. ] Evolution in Methods of Pollination. 73 
tion to the reciprocal wants of plants and their visitors, from 
fructifications essentially like the spore-bearing spikes of the 
heterosporous Equisetums of which geologists write, this 
ought to be known by every student, and everyone should be 
able to see from the manual that, in each order, the method 
of fertilization is to a certain extent an index of the degree 
of specialization of the reproductive apparatus, the most im- 
portant part of the plant. In many orders there is a most 
beautiful transition from anemophilous (usually polygamous, 
moncecious or dicecious) species through almost exclusively 
self-fertilized hemaphrodite ones to those that are incapable 
of self-fertilization. For example, in the Ranunculaceae, in 
the gradation from the wind-blown inflorescences of polyga- 
mous Thalictrums to the inconspicuous, almost exclusively 
self-fertilized flowers of Myosurus minimus ; from this to the 
genus Ranunculus (whose small-flowered species, such as 
like, Spore-bearing stalks of the ancestors of our dicotyledons. 
At a certain stage of development, these changing plants 
will be perfectly adapted to neither wind nor insect fertiliza- 
tion; then those individuals whose stamens and pistils are 
