so 



POLLEN. 



ble chances are so numerous, that it is hardly possible, in the order 

 of nature, that a pistillate plant should remain unfertilized. The 

 particles of the poUen are light and abundant, and the butterflies, 

 honey-bees, and other insects, transport them from flower to flower. 

 The winds also assist in executing the designs of nature. 

 The pohen of the Pines and Firs, moved by winds, may be seen 

 nsing like a cloud above the forests; the particles being dissemina- 

 ted, fall upon the pistillate flowers, and rolling within their scaly en- 

 velopes, fertilize the germs. 



A curious fact is stated by an Italian writer, viz. that in places 

 about forty miles distant, grew two palm-trees, the one without sta- 

 mens, the other without pistils ; neither of them bore seed for many 

 years ; but in process of time, they grew so tall as to tower above 

 all the objects near them. The wind, thus meeting with no obstruc- 

 tion, wafted the pollen to the pistillate flowers, which, to the aston- 

 ishment of all, began to produce fruit. 



The number of plants in which the pistils and stamens are on dif- 

 ferent flovrers, is few, compared to those which have these important 

 organs enclosed v/ithin the same coroha; as in our herbaceous 

 plants, and the trees of hot countries, whose leaves being always 

 present, might impede the passage of the pollen from other trees. 

 On the contrary, the trees of cold climates have generahy the sta- 

 mens and pistils on separate flowers, blossoming before the leaves 

 come forth, and in a windy season of the year. Those which blos- 

 som later, as the oak, are either peculiarly frequented by insects, or 

 like the numerous kinds of firs, have leaves so little in the way, and 

 pohen so excessively abundant, that it can scarcely fail of gaining 

 access to the pistiUate flower. 



In all cases the pollen and stigma are in perfection at the same 

 time ; in those flowers where the stamens and pistils are together, 

 and of an equal length, some are drooping and some erect, but 

 where the stamens are longer than the pistil, the flov/er is usually 

 erect ; where they are shorter, the flower is pendent ; nature thus 

 provides for the fertilization of the germ by the fall of the farina upon 

 the stigma. 



'~~ Fig. 85, at A, re- 



presents a flower 

 of the genus Eu- 

 phorbia.* It is mo- 

 n<Ecious ; in the 

 centre of the peri- 

 anth, a, is the infer- 

 tile fl.ower, consist- 

 ing of several dou- 

 ble stamens, c c, 

 upon jointed fila- 

 ments, del. b, is the 

 fertile flower, v/ith 

 a petal-like stigma. 

 At B, is the same 

 flower before blos- 

 soming; it is re- 

 presented as cut 



* EcPHORBiA iUyrica. — Mirbel. 



Facts stated by an Italian writer— Trees of hot countries have mostly stamens and 

 pistils on the same corolla— Trees of cold countries have the stamens and pistils on 

 separate flowers— Methods by which the objects of nature are accomplished— Explain 

 Fig. 85. 



