19 
CHLORIDE. 
Spartina. Leptochloa. 
Eleusine. 
Chloris. 
Beckmannia. 
Cynodon. 
Astrebla. 
Bulbilis. 
HORDES. 
Secale. * Nardus. 
Hordeum. Lolium. 
Asperella. Triticum. 
FESTUCACE. 
* Boissiera. * Echinaria. 
* Schismus. Cynosurus. 
Fest " 
Gynerium. Leptochloa. 
Melica 
Koeleria. 
oa. 
Panicularia. 
* Lamarckia. 
BAMBUSE E. 
Arundinaria. 
| * Bambusa. 
THE PLUMULE-SHEATH. 
This peculiar structure is found in all grasses, completely surround- 
ing and protecting the plumule, with the exception of a small opening 
or slit toward the apex on the side opposite to the scutellum. At ger- 
mination the young leaves break through this sheath, which soon 
afterwards dies down. The plumule-sheath always has two distinct 
vascular bundles situated laterally and slightly inclined toward the 
scutellum. Considerable controversy has arisen as to whether this 
organ is a part of the cotyledon or whether it represents the first true 
leaf of the embryo. This will be treated of later under the chapter on 
the homology of the parts. It usually originates directly under the 
plumule and close to the insertion of the scutellum, although it is 
