350 BOTANICAL GAZETTE [MAY 
of the chalazal region of the seed was studied in some detail, and the attempt is 
made to correlate the structure with the functions of this region in conveying 
food to the young seed after the cutinization of its coats, and in providing for the 
necessary gaseous interchange with the seed. 
The embryo-sac is developed, without division to tapetum or megaspores, 
from a hypodermal cell of the ovule. The antipodals are evanescent, and the 
multinucleate endosperm-sac grows to occupy the whole peripheral region of the 
campylotropous ovule, and is finally filled by the strongly curved embryo. The 
endosperm is a single layer of cells throughout, though much thicker in the 
micropylar cap of endosperm which covers the radicle in the mature seed. This 
part of the endosperm seems the more important, and evidently serves the part of a 
digesting and absorbing structure in transferring food material from the nucellus 
to the embryo during its later intraseminal development and the early stages of 
germination. This function is indicated by the position of the endosperm, by 
the nature of its cell contents, and by the fact that seeds from which the endo- 
sperm has been removed do not germinate. 
This work of Miss Gress adds another series of perisperm-containing seeds 
to those in which Jonnson™? and Lewis‘? have shown that the endosperm is 
not for the storage of food for the embryo, but serves to digest and pass on to the 
embryo, before and during germination, the starch stored in nucellar tissue.— 
UNCAN S. JOHNSON. 
The structure of Trigonocarpus.—Scorr and MasLen*3 have been investi- 
gating the structure of certain species of Trigonocarpus, a common seed-genus 
of the British Coal-measures. The species discussed are T. Parkinsoni, which 
name replaces the more familiar T. olivaeforme, and T. Oliveri, a new species. 
The general oval form of the winged body of the seed and its very prominent 
micropylar beak are the familiar features. ‘The testa is distinctly cycadean in 
character, the outer fleshy and the stony layers being very evident, while there 
are traces of the inner fleshy layer. The micropylar beak is often as long as the 
body of the seed, and in some specimens twice as long, and is peculiar in bearing 
two broad wings, whose real nature is problematical. The nucellus and testa 
are free throughout, a feature, presumably an ancient one, belonging to certain 
paleozoic seeds. The vascular system of the seed is in general that described by 
OttveR for Stephanospermum, namely, an outer hal running in the outer 
fleshy layer, and an inner system traversing the nucellus. This nucellar system 
in Trigonocarpus is quite conspicuous, forming a S eticalls continuous sheath” 
in the lower part of the nucellus, and traceable through the whole length of the 
nucellus, almost to the base of the pollen chamber. The pollen chamber is rela- 
Ir sen GAZETTE 34:321-340. pls. 9, 10. 1902. 
2 Bot. GAZETTE 40:79. 1905. 
13 Scott, D. H., and MASLEN, ARTHUR J.. The structure of the paleozoic seeds 
Trigonocarpus Parkinsoni Bro: rongniart and eo amyl ive Oliveri, sp. nov. Part I. 
Annals of Botany 21:89-134. pls. II-I4. 1907. 
