POLLINATION AND FECUNDATION. 47 



(for which no additional directions need be liere repeated), but also be seen 

 by each pupil when the agencies are in actual operation. Therefore make 

 daily observation at various hours, carefully state the results in the note- 

 book and report in the class-room. The behavior of the various insects vis- 

 iting the flowers, their mode of obtaining nectar, and their agency in trans- 

 ferring pollen and incidentally depositing some of it on the stigma, should 

 be especially observed. The flowers whose pollination is effected by the 

 wind as well as those pollinated through the agency of insects, should be 

 critically studied. The teacher can prolong this phase of the work accord- 

 ing to disposable time and opportunity for visiting blooming plants in suf- 

 ficient variety. 



2. When the pollen from the anthers of a perfect flower is 

 applied to the stigraa of the same flower the process is called 

 self-pollination, or close-pollination. But if the pollen of one 

 flower is applied to and germinates on the stigma of a diSerent 

 flower, it is called cross-pollination. It would naturally be 

 expected that in hermaphrodite, i. e. perfect flowers, self-pol- 

 lination would almost invariably obtain. But it is known that 

 cross-pollination is the rule and self-pollination the exception. 

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

 structure of the flower to prevent self-pollination. Some 

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

 hermaphrodite flowers — a showy form, in which cross-poUina- 

 tion occurs, and an inconspicuous form where self-pollination 

 necessarily takes place. 



3. When the transport of the pollen is effected by the wind, 

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

 philos, loving). Such are the Pines, Oaks, Hickory, Walnut, 

 Alder, Grasses, Sedges, Hemp, Hops, etc. They are character- 

 ized by the production of an enormous 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. The flowers are mostly greenish, 

 or of dull colors and inconspicuous. The stigmas are gener- 

 ally large, often furnished with hairs or dissected into plumes, 

 for the retention of the grains that may come in contact with 

 them. The anthers are often suspended on capillary filaments 

 so as to be more directly exposed to the action of the wind. 



