586 ON SEEDLINGS 



Cyperus Iria, C. Papyrus, Isolepis Savii, Carex caucasica, C. 

 lagopina, and Kobresia caricina). He points out that the struc- 

 ture of the embryo is somewhat different from that of the Grass- 

 embryo, connecting the latter with the typical liliaceous type. 

 The lower end is always occupied by the radicle without any 

 marked root-sheath, the upper by the cotyledon. The Cyperaceae 

 agree with the Grasses in the distinct development of the coty- 

 ledonary sheath, which encloses the clearly indicated first leaf. 

 In germination the cotyledon alone at first grows. The 

 sheath elongates, breaks through its coverings, and bends 

 geotropically upwards. 1 The middle portion of the cotyledon 

 then grows rapidly, and pulls the main root out of the seed. 

 Before the appearance of the root, a circlet of long hairs is 

 developed at the base of the cotyledonary sheath, probably on 

 the portion corresponding to the hypocotyl which does not 

 develop. The hairs take the place of the root in the early 

 stages. The primary root gradually develops while the first 

 leaf appears from the sheath. Ultimately the primary root 

 elongates considerably, the first adventitious root breaks from 

 the base of the cotyledonary sheath, and other leaves succeed 

 the first. The end of the cotyledon which remains in the 

 seed swells until, after absorbing all the endosperm, it almost 

 fills the interior. 



GRAMINEJS. 



Benth. et Hook. Gen. PI. iii. 1074. 



Fruit and Seed. The ovary is sessile or shortly stalked, 

 erect, entire or sub-bidentate at the foot of the styles. It is 

 one-celled and contains one ascending anatropous ovule, fixed 

 near the base or laterally, and often separable with difficulty 

 from the ovary. The fruit is termed a caryopsis, and is inde- 

 hiscent, usually small, and included in the glume and pale with 

 a fragment of the rhachilla, together with which or the whole 



1 Well shown by Mirbel in Scirpus romanus in Elements de Physiologic 

 Vtgttale, p. 59, fig. 4. 



