VIII 



KACHILLA, "WEB," ETC. 



131 



palea as tapering into a sharp point (awn-point). It must 

 be admitted that the distinction is somewhat artificial, but 

 it has its advantages in practice. 



Fig. 50. Bromussterih's. a, "seed," 

 nat. size; b and c, ditto, x about 

 2. Nobbe. Cf. Figs. 80 and 81. 



Fig. 51. Fc'ttiica sylvatica. a, 

 "seed," nat. size; b and c, 

 ditto, X 8. Nobbe. Cf. Fig. 78. 



The rachilla (Fig. 41), when present, often affords good 

 characters, and in a few cases is relied on for the dis- 

 tinction of "seeds" otherwise much alike — e.g. Lolium 

 perenne and Festuca elatior ; and similarly with the 

 presence or absence of hairs {Digrapliis, Arundo, &c.) 

 or " web " (Poa) at the base of the " seed." (Figs. 55, 69.) 



On germination the primary root of the embryo 

 usually emerges and at once plunges into the soil, but 

 soon ceases to grow, and the secondary roots (and sub- 

 sequently adventitious rootlets from the lower internodes) 

 soon give the peculiar fibrous character so well known in 

 grass-roots. 



9—2 



