The Comparative Morphology of the Embryo and 
Seedling in the Gramineae. 
BY 
ETHEL SARGANT, F.L.S. 
AND 
AGNES ARBER, D.Sc., F.L.S. 
With Plates IX and X and thirty-five Figures in the Text. 
T HE embryo of the Grasses is sufficiently unlike that of most Mono¬ 
cotyledons to render exact comparison difficult. No question arises 
concerning the stem-bud and primary root ; they are par¬ 
ticularly clear in the Grass embryo, because it is more 
completely differentiated in the ripe seed than that of most 
Monocotyledons. But the parts which feed and protect 
them—the scutellum, coleoptile, coleorhiza, and epiblast— 
retain these non-committal names because botanists are 
not yet agreed on their respective homologies. 
Before 1872 the only evidence considered was the 
structure of the embryo within the seed, or immediately 
on germination. At that age the vascular tissue is not 
sufficiently differentiated to be traced with certainty. 
In 1872 Van Tieghem published a paper in which he 
compared the vascular skeletons of many seedling Gramineae 
with each other, and with those of certain other selected 
monocotyledonous seedlings. He interpreted the structure 
of the embryo within the seed in the light of its later de¬ 
velopment. In a subsequent paper (1897), the same author 
pursues the subject. Publishing no new figures, he accepts 
a correction of fact made by Miss Lewin (’ 87 ), Bruns (’ 92 ), 
and Schlickum (’ 96 ), but otherwise depends mainly on the 
evidence published in 1872. His interpretation of that 
evidence is, however, quite different. 
Since that date the method then introduced by Van 
Tieghem has been applied to seedlings from many families, with a precision 
impossible before the introduction of the microtome. Indications of race 
Text-fig. i. 
Avena saliva, L. 
Embryo in median 
section, x 18. 
[Annajs of Botany, Vol. XXIX. No. CXIV. April, 1915.] 
M 
MAY 25 19.15 
