12 



lateral, much-branched, feather-like stigmas. The single 

 ovule is slightly ascending from the placenta-like suture 

 and becomes later more or less inverted into the camp\'lo- 

 tropous form. 



The grain or ripe fruit is termed a Caryopsis (Fig. 3). 

 The ovar)' wall and shrivelled remains of the two ovular 

 integuments adhere closely around the floury endosperm 

 of the seed — they constitute the familiar bran removed 

 during milling operations. The highly differentiated 

 embryo has a slightly curved axis, with its root and shoot 

 portions separated by the hypocotyl, several primordial 

 leaves sheathing the plumule, and often the primordia of 

 several rootlets. It is set obliquely at the lower end of 

 the grain and encased in a membranous sheath formed 

 by the scutellum and coleorhiza. The epiblast, a small 

 cellular outgrowth inserted opposite to the cotyledon, is 

 supposed to represent a second cot\-ledon, but its 

 homology has not been determined. 



Post-embryonic developments, those following 

 germination of the grain, show the now more conspicuous 

 coleorhiza pierced by the growing rootlets (Fig. 4). The 

 pointed apical end of the cotyledon appears above the 

 soil, and the first foliage leaf pushes its way through the 

 cotyledonary sheath, followed by the plumule, whicli 

 develops into the stem or main axis, and finall\- bears the 

 terminal head or spike of flowers. 



THE MICROSPORANGIUM. 



The primordia of the three stamens arise as minute 

 papillae upon the rachiUa of a spikelet beneath the carpel, 

 and are extensions of its dermatogen and periblem cells. 

 The part destined to form the anther, or sorus of Micro- 

 sporangia (Fig. 5), takes an oblong, slightl)- hour-glass 



