CHAPTER II. 



FLOWERING AND FLOWERLESS PLANTS— STRUCTURE 

 OF THE SEED. 



All the higher forms of plant life are distinguished as being 

 able, at some time or other of their existence, to produce 

 flowers. 



It is this fact which causes the Vegetable 

 Kingdom to be divided into the two sub- 

 kingdoms of Flowering Plants or Phanero- 

 gams, and Flowerless Plants or Crypto- 

 gams. 



In the present work we shall deal entirely 

 with the Phanerogams. 



The point in which all of these plants 

 agree is that they spring originally from 

 seeds. To understand a seed thoroughly, it 

 is well to commence with a large specimen, 

 as, for instance, a Broad Bean, Haricot, or 

 a Pea. 



If we examine a Broad Bean carefully, fig. 

 we notice that it has an elongated shape. 

 At one end there is a scar or mark. This is 

 the point by which the seed is attached to 

 the fruit, and is known as the hilum. At 

 one end of this there is a minute hole. This 

 can be readily seen by allowing the bean to 

 soak in hot water for a short time ; then on 

 taking it out and squeezing it a drop of 

 water is seen to escape through the aperture. 

 This hole, which leads into the interior of 

 the seed, is called the micropyle. 



Next, taking a sharp penknife, we find that we can peel 



£2 



Broad Bean. 

 A^ seed, with one coty- 

 ledon removed : c, re- 

 maining cotyledon : 

 kn^ the plumule ; w, 

 the radicle ; j, the sper- 

 moderm. B, germi- 

 nating seed : J, sper- 

 moderm, a portion torn 

 away at / ; «, hilum : 

 st^ petiole of one of the 

 cotyledons ; /p-, curved 

 epicotyledonary por- 

 tion of axis, i; he, 

 short hypocotyledonary 

 portion of axis ; h, 

 main root ; itis, its 

 apex : kn, bud in axil 

 of one of the cotyle- 

 dons. (After Sachs,) 



