l'h'()\ISI(>.\S FOR ATTUACTIXa IXSECTS 



!)1 



The latter must he considered iii(hvi(hiall\ . The former are two — 

 namely, throufijh the agency of tlie wind and throufj;h that of insects 

 (or occasionally other animals). 



Anemophilous and Entomophilous Flowers. — Flowers adapted to the 

 former methods are called Anemophilous; those adapted to the latter 

 are called Entomo])hilous. Occasionally the flower is so formed that 

 the movement of the water during rains, or in streams, effects pollina- 

 tion. 



Provisions in Anemophilous Flowers. — The activity of the wind hcing 

 heyond the control of the flower, the adai)tati()n of the structure of an 

 anemophilous flower is limited to securing the benefits of such action 

 when it comes into play. This consists chiefly in (1) a gregarious habit 

 — the growing together in great numbers of individuals of one kind, as in 

 the case of grasses and of most of the forest trees of temperate latitudes; 

 (2) a very abundant j)()llcn ('.]), which is loosely fixed, one method 

 being illustrated by Fig. 2()7, light and easily 

 removed and transported; and (4) the dispo- 

 sition of the ovule of gymnos])erms, and the 

 form and disposition of the stigma and con- 

 nected parts of angiosperms, so as to catch 

 the pollen. All these provisions may be 

 readily seen to affect the process in the case 

 of Pitiiift pal list r is, for example. In this 

 l)laiit the ])()llcn-grains contain several cells, 

 all but one of them empty, thus decreasing 



tlicir specific gravity. They are produced in such great abun- 

 dance that the crop, carried by strong winds, has been known to 

 fall at a great distance as a thick deposit, the so-called "sulphur- 

 showers" of history. The trees are densely massed, to the exclusion 

 of almost all others, and bear innumerable cones (Fig. .SfiO), each 

 consisting of numerous scales, outwardly flaring, and so (lisi)ose<l as 

 to catch many of the j)ollen grains and guide them downward to the 

 little pockets at their bases. 



Provisions in Entomophilous Flowers. In entonioi)hilous (lowers, such 

 provisions as aboNc described for the utilization of the i)()llen-carr\ing 

 forces, nuist be preceded by others of a dilVereiit nature, eal(ulate(j to 

 first set in motion and attract these forces. 



Provisions for Attracting Insects. l*i-()\isi(»Ms for atti-acting external 

 agents are found chiefly in the form, coloration, and size of the Hower 

 or of one or more of its i)arts, the ])roduction of fragrant and nutritive 



Fig. 2()7 



Anemophilous flower of 

 a grass. 



