26 
glume some distance from the apex, that part between the insertion 
and the apex is regarded as corresponding to the ligule, and, in conse- 
quence, to the plumule-sheath. That part of the glume below the 
insertion of the awn is regarded as the sheath of the leaf, while its 
analogous structure in the embryo has been arrested in its development. 
Colomb,' who has investigated the stipules of many plants, also takes 
up the ligule and sees in it an analogy to the stipules of Potamogeton 
and Smilax. Celakovsky? makes a comparison between these, adding 
another plant, Ficus elastica. He carries his homology still further to 
the mosses, believing that the moss capsule is homologous to the 
cotyledon and the seta or their bases to the hypocotyl. 
DETAILED DESCRIPTIONS OF FRUITS. 
Tribe MAYDEJE. 
The fruits of the genera of this tribe are large, ellipsoidal or round- 
ish, and inclosed, with the exception of Zea, in a hard capsule formed 
of the glumes or of part of the articulate rachis. They have a very 
large embryo, with the scutellum almost completely surrounding the 
plumule. 
Coix lachryme-jobi L. (figs. 1, 2 A-G, Pl. I. The structure of the 
embryo of Coir resembles that of Zea mays, the main difference con- 
sisting in the former possessing four lateral radicles. Only three are 
shown in fig. 1, the fourth and uppermost one not being in the same 
plane. Fig. 2 A represents a transverse section through the upper 
part of the plumule, showing the plumule-sheath with its two bundles 
and the first and second true leaves in their normal position. .A see- 
tion through the base of the plumule (fig. 2 B) shows the plumule- 
sheath and a small part of the first, true leaf. Within is the axis with 
its numerous bundles which belong to the leaves of the plumule. t 
At € is the axis, with its numerous bundles and the plumule-sheath. 
Some of the bundles in the periphery of the central cylinder unite and 
branch off into the plumule-sheath on each side. A little lower down, 
between the insertion of the plumule-sheath and that of the scutellum 
the axis appears with its numerous bundles arranged in the periphery 
of the. central cylinder (fig. 2 D). Fig. 2 E shows the scutellum 
iuserted on the axis by its broad, fibro-vascular bundle, at the same — 
time cutting through the first lateral radicle on the opposite side. A 
number of duets are scattered here and there in the axis. The axis 
terminates in the lowermost radicle, the central cylinder having six 
distinct ducts or vessels, Fig. 2 F shows a section through the upper 
part of the lowermost radicle and one of the lateral radicles, while G 
represents a section through the lowermost radicle, Each radicle is 3 
provided with a root-cap while the coleorhiza surrounds them all. The 
} Recherches sur les stipules. Ann. des Boi. nat. Ser. 6, 1: 19. 1887. 
Ueber die Homologien des Grasembryo. Bot. Zeit., Sept., 1897. 
