THE FLOWER 55 



di, two ; oikos, house). In monoecious and dioecious plants 

 it is evident that the transport of the pollen from the 

 staminate to the pistillate flowers must in some way be 

 effected in order to accomplish fertilization. Even in 

 hermaphrodite flowers it is found to be a rare case that 

 the pollen, wholly unaided, falls on the stigma of the same 

 flower. 



70. When the pollen of a flower is applied to, and acts 

 on, the stigma of the same flower, the process is called 

 close-fertilization, or self-fertilization. But if the 

 pollen of one flower is applied to, and acts upon, the stigma 

 of a different flower, it is called cross-fertilization. It 

 would naturally be expected that in hermaphrodite flowers 

 self-fertilization would almost invariably obtain. So it was 

 taught until very recently. Now it is known that cross- 

 fertilization is the rule, and self-fertilization the exception. 

 In fact, there is in the majority of cases something in the 

 structure of the flower to prevent self-fertilization. Many 

 plants, as the Oxalis, Violet, etc., have two sets of herma- 

 phrodite flowers — a showy form, in which cross-fertilization 

 occurs, and an inconspicuous form, where elose-fertiliaatiou 

 necessarily takes place. 



71. When the transport of the pollen is effected by the 

 wind, the flowers are said to be anemophilous (Gr. 

 anetnos, wind ; philos, loving). Such are the Pines, Oaks, 

 Hickory, Walnut, Alder, Grasses, Sedges, Hemp, Hops, 

 etc. They are characterized by the production of an enor- 

 mous quantity of pollen. This insures the contact with the 

 stigma of at least a small portion of the pollen. It is light, 

 dry, incoherent, and readily transported great distances, 

 sometimes forming "showers of sulphur." The flowers are 

 mostly greenish, or of dull colors, and inconspicuous. The 



