MONOCOTYLEDONES. 



451 



cate their real affinities. Unfortunately for us, however, 

 none of our systematic manuals follow any of the Continen- 

 tal systems ; we are compelled, therefore, to use for the pres- 

 ent the prevailing form of the Candollean system. In this 

 book the sequence of the groups is the reverse of that in 

 most American and English books, in order to bring the ar- 

 rangement of Angiosperrns into harmony with that of the 

 rest of the vegetable kingdom. 



SUB-CLASS I. MONOCOTYLEDONS. 

 (Endogence of De Candolle.*) 



550. In these plants the first leaves of the embryo are 



alternate, hence we say 

 that they have one cotyle- 

 don. The venation of the 

 leaves is for the most part 

 such that the veins run 

 more or less parallel to 

 one another, and when 

 they anastomose enclose 

 four-sided areolae ; rarely, 

 however, their veins are 

 irregularly distributed, 

 and they anastomose so as 

 to form an irregular net- 

 work. 



Fig. 331. Longitudinal section of the seed 

 of Indian corn (Zeu Mais), c, adherent wall 

 of the ovary ; , remains of the style \fs, 

 base of the ovary ; all the remainder of the 

 figure is the true seed ; eg, ew, endosperm ; 

 ., ., cotyledon of embryo; e, its epider- 

 mis ; , plumule ; w (below), the main root ; 

 teg, the root-^henth ; w (a'>ove), adventitious 

 roots springingfrom the first iuteruode of the 

 stein, x 6. After Sachs. 



has its broad dorsal surface in contact 



The- germination of Monoco- 

 tyledons may be illustrated by 

 a couple of examples. In tlie 

 seed of tlie Indian corn the 

 embryo lies partly imbedded 

 in one side of the large endo- 

 sperm (Fig. 331). The first leaf 

 of the young 1 plant (the cotyle- 

 don or scutellum, Fig. 331, $c ) 

 with the endosperm ; anteriorly 



* From the Greek evfiov, within, and yevetv, to bring forth. The 

 name was given under the false impression that these plants were 

 " inside growers," and the Dicotyledons " outside growers." 



