4 A USTRALIAN BOTANY. 



known by the venation or marking of their leaves, which 

 have straight or curved unbranched lines running almost or 

 quite parallel with the midrib, which is a continuation of 

 the leaf-stalk, as a rule running through the middle of the 

 leaf. Monocotyledons include grasses, palms, aloes, rushes, 

 the ordinary garden lilies, and many other species. They 

 are also termed endogens or ' inside growers.' Most dicoty- 

 ledons, on the contrary, have their leaves marked with a 

 network of veins, branching more or less over the leaf. 

 The plants belonging to this class are also termed exogens 

 or ' outside growers.' A further explanation of the terms 

 endogen and exogen will be given in a future lesson. 



The Plumule is the bud in the embryo or first stage of 

 growth, indicating the future stem. In some seeds, as in the 

 pea, it is plainly perceptible ; in others it is very indistinct. 



At the summit or apex of some seeds, as of the Orange, 

 Almond, or Pea, a brown spot is observed, formed by the 

 union of certain vessels which proceed from the hilum ; 

 this spot is the chalaza, and it is connected with the hilum, 

 or base of the seed, by a vessel which passes alone the face 

 of the seed, and is termed the raphe. 



The Radicle (c, fig. D) is situated below the plumule 

 (A, fig.- D), and is the germ (starting-point) of the root. It 

 always points to the micropyle or foramen (3, fig. A), which 

 is a small hole in the hilum {umbilicus) or scar through which 

 nourishment is conveyed to the young seed or nucleus 2 by 

 the funiculus (cord) attaching it to the place?ita of the seed- 

 case. The hilum, like the plumule and radicle, is distinct 

 or obscure in different plants. It is plainly marked in the 

 pea and bean ; indistinctly in the wattle. 



1 Nucleus, a central mass or kernel. 



