METHODS OF POLLINATION 



171 



could not be deposited in the funnel-shaped stigma. The 

 moth resting quietly in the flower during the day, at dusk 



crowds down over 



the stamens, digs 



out some of the 



pollen mass with 



her foot, passes 



down on the ovary 



over one of the 



furrows directly 



over where the 



ovules are located, 

 The position of p WM &a pierces the ovary 



on the stamen of Yucca 'XL, 

 With 



B 



when collecting pollen and 



^^r^c, 

 OVlpOSl- 



Fig. 131. 



A mature capsule of Yucca, showing 

 perforations made by larvae of Pro- 

 nuba in escaping. After Riley and 



when thrusting it into the , i _.1 _...<, _ 



stigmatic funnel. After tor and plants an 

 egg in an ovule. 



Then she passes on to the end of 

 the pistil and crowds the pollen 

 into the funnel-shaped opening of 

 the stigma. She repeats this proc- 

 ess several times, depositing sev- 

 eral eggs and placing an abundance Trelease - 

 of pollen in the stigma, which insures the development of a large 

 number of seeds, some of which can be used for food by the 

 young larvae. 



CROSS-POLLINATION BY THE WIND. 



286. While wind pollination takes place in quite a variety 

 of plants, it is the chief method among the grasses, cereals, Indian 

 corn, the amentiferous trees and shrubs (those bearing catkins), 

 and among the conifers. Whoever has been in a cornfield at the 

 time of pollination will realize this. In the pines among the 

 conifers, the pistillate cone stands erect and the scales flare out- 

 ward during pollination. The pollen is caught on these scales 

 and rolls down to the lower end, where it is caught in a viscid 

 substance in the micropyle of the ovule. 



