282 



The Living Plant 



of the egg in animals, and hence called the egg-cell. Thus much 

 for the female reproductive apparatus; turning now to the male, 

 we find it in the pollen grain, which, examined microscopically, 

 is found to consist of at least two cells (figure 98), of which one 



gives rise to the male, or 

 sperm, cells, presently to be 

 further described. Such is 

 the floral structure, and such 

 the appearance and locations 

 of the sexual cells, when fully 

 ripe and ready for fertiliza- 

 tion. 



The process of fertilization 

 itself can be followed in de- 

 tail by aid of the microscope, 



Fig. 90. — Interior view of a typical flower (of i • i • • i i 

 Peony), showing the four distinctive parts,— and IS shoWU Ul eSSeutials by 

 the outer calvx, made up of sepals, the more i • -i ^ • / r- 

 showy corolla, made up of petals, the many OUr generalized draWUlg (tig- 

 stamens, and the two pistils, which in this ^^^ gg)^ ^pj^g fjj.g^ g^^p ^g p^J, 

 case show typical ovaries, but very short ' r- r 

 styles and small stigmas. (Copied from linatioil, Or the transfer of the 

 Strasburger's Textbook). ■ c 



pollen gram from the anther 

 to the stigma, and since the pollen is usually brought from a sepa- 

 rate plant, the process is far more elaborate than one would 

 imagine, and one, withal, which involves so many striking and 

 interesting features that we must treat the subject in a chapter 

 by itself; and that chapter follows. When the pollen grain 

 reaches the stigma, to which it is held by a certain roughness 

 aided by a sugary stickiness, it immediately begins to send 

 out a slender tube. This tube, which carries in its tip two 

 nuclei that represent the essential parts of two male cells, grows 

 down into the tissues, through which it dissolves its way 

 by aid of enzymes secreted by the tip, the dissolved substance 

 being absorbed for food ; and thus the tube literally digests its way 

 down through the tissues of stigma and style to the cavity of the 

 ovary. Here it passes out from the solid tissue, and, guided as it 



