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, tlieref ore, 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. MONOCOTTLEDONES. 



550. 



(Endof/enm of De Candolle.*) 

 -In these plants the first 



Fig. 331. Longitudinal section of the seed 

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

 of the ovary ; n, remains of the style \fg, 

 base of the ovary ; all the remainder of the 

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

 to *, cotyledon of embryo; e, its epider- 

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

 ,<, theroot-shenth; w (above), adventitious 

 root s springing fn>m the first iuteruodo of the 

 teui. x 0: After Sachs. 



has its broad dorsal surface in contact 



leaves of the embryo arc 

 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. 



The germination of Monoco- 

 tyledons may be illustrated by 

 a couple of examples. In the 

 seed of the Indian corn the 

 embryo lies partly imbedded 

 in one side of the large endo- 

 sperm (Fig. 331). The first leaf 

 of the young plant (the cotyle- 

 don or scutellum, Fig. 331, gc, 

 with the endosperm ; anteriorly 



* From the Greek Ivtiov, within, and yfi-etv, to bring forth. The 

 name was given under the false impression that these plants were 

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



