8 



a number of circular openiugs closed by lids, L, L', L", R, 

 underueatli whicli the inner membrane, S, is thickened. 

 When the flower opens in early morning the pistil exudes a 

 quantity of sticky fluid on and about the numerous fine 

 hairs growing on the stigma, by means of which the pollen 

 grains are caught when transported by the wind and in- 

 sects. Very soon after the pollen lodges on the pistil, the 

 lid, L fig. 3, is thrown aside by the growing of the inner 

 membrane coat, S, into a tube. This tube pushes its way 

 between the tissues of the stigma down the style and into 

 the ovary at d fig. 2, where the end of the tube opens and 

 the female germ becomes fertilized, thus producing the seed. 

 The most remarkable fact in regard to this matter is the 

 rapid growth of the pollen tube in such a short time, be- 

 cause the work must be accomplished in twenty-four hours. 

 Shortly after the fertilization has taken place in the 

 ovary, the j^etals, stamens and the upper portions of the 



pistil wither and fall 

 off, leaving the ovary 

 and its surrounding 

 involucre leaves. This 

 ovary, as has been al- 

 ready stated, is the 

 young boll containing 

 the rapidly growing 

 seeds with their fiber 

 coatings. A section of 

 a half grown boll is 

 given in fig. 4. This is 

 a longitudinal section 

 showing seeds at oo, 

 and the cells (or car- 

 2oels) FF which will be 

 filled with the staple 

 when the boll is com- 

 plete in its growth. 

 SS represent the ca- 

 lyx. The involucre 



-•^-■F 





7>.H.Mt.U l>cl . 



is not shown in the drawing. 



