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PHARMACEUTICAL BOTANY 
POLLINATION 
Pollination is the transfer of pollen from anther to stigma and 
the consequent germination thereon. It is a necessary step to 
fertilization. 
When the pollen is transferred to the stigma of its own flower the 
process is called Close or Self-pollination; if to a stigma of another 
flower, Cross-pollination. If fertilization follows, these processes are 
termed respectively, Close or Self-fertilization and Cross-fertilization. 
Close-fertilization means in time ruination to the race and happily is 
prevented in many cases by (a) the stamens and pistils standing in 
extraordinary relation to each other, ( b ) by the anthers and pistils 
maturing at different times, (c) by the pollen in many cases germin- 
ating better on the stigma of another flower than its own. 
The agents which are responsible for cross-pollination are the wind, 
insects, water currents, small animals, and man. 
Wind- pollinated flowering plants are called Anemophilous; their 
pollen is dry and powdery, flowers inconspicuous and inodorous, as 
in the Pines, Wheat, Walnut, Hop, etc. 
Insect- pollinated plants are called Entomo philous . These, being 
dependent upon the visits of insects for fertilization, possess bril- 
liantly colored corollas, have fragrant odors, and secrete nectar, a 
sweet liquid very attractive to insects which are adapted to this work 
through the possession of a pollen-carrying apparatus. Example: 
Orchids. 
Plants pollinated through the agency of water currents are known as 
Hydrophilous. To this class belong such plants as live under water 
and which produce flowers at or near the surface of the same. Exam- 
ple: Sparganium. 
Animal-pollinated plants are called Zoo philous. Some plants like 
the Nasturtium and Honeysuckle are pollinated by humming birds. 
Before the pollen grain has been deposited upon the stigma and 
during its germination thereon, a series of events affecting both the 
pollen grain and the embryo sac occur which result in the ultimate 
formation of the male and female gametophytes. 
Maturation of the Pollen Grain and Formation of the Male 
Gametophyte. — The substance of the microspore (pollen grain) 
divides into two cells, the mother and tube cells of the future male 
