The Anatomy of the Scutellum in Zea Mais. 
BY 
ETHEL SARGANT AND AGNES ROBERTSON, B.Sc. 
With Plate V. 
B OTANISTS have long been familiar with the external structure of 
the Grass-embryo, which is sufficiently different from that of the 
embryo in other Monocotyledons to leave some doubt as to the homology 
of their parts. We began the examination of several Grass seedlings in 
the autumn of 1902, hoping that their anatomy at a period soon after 
germination might throw light on this vexed question. We did not propose 
to monograph the family from this point of view, but, having chosen a few 
genera from very different parts of it, to compare their seedlings anato- 
mically with each other, and with those of the Monocotyledons already 
worked out by one of us. 
Even this skeleton scheme has not yet been completed, for we have 
not succeeded in getting all the material desirable. Side issues of some 
importance have been raised, however, and in particular the anatomical 
structure of the Maize scutellum offers some features of interest which we 
believe to be still undescribed \ They are clearly bound up with its 
function as a sucking organ, and the subject is thus a digression from 
the main morphological line of research, and is more conveniently treated 
in a separate form. 
External Morphology of Embryo* 
Within the ripe fruit the main axis of the embryo is triply protected* 
Embryo and endosperm alike are enclosed in the dry covering of the grain. 
When a part of this is removed, the whole embryo is seen lying against 
one face of the endosperm (Fig. 3, PI. V, cf. also Figs. 1 and 6 ), The 
second covering is formed of the scutellum (sc. in Figs. 1, 5, 7), a cushion- 
like structure which is wrapped round the embryonic axis and still 
conceals the greater part of it in the first days of germination (Fig. 3). 
1 Ethel Sargant and Agnes Robertson, ‘ On some Anatomical Features of the Scutellum in 
Zea Ma'is.’ Report Brit. Assn., Southport, 1903, p. 860. 
[Annals of Botany, Vol. XIX. No. LXXIII. January, 1905.] 
