1912] STEVENS—SEED OF BUCKWHEAT 65 
closely packed cells, filled with starch. In its development the 
cellular portion has been crowded well down toward the base of the 
ovule. Even in the mature fruit, however, a space containing the 
remains of the undeveloped basal portion of the embryo sac is 
always present in the chalazal region (fig. 7). 
The absence of a perisperm in the buckwheat does not of course 
exclude the possibility of its occurrence in other members of the 
Polygonaceae. That such a variation is sometimes found in nearly 
related genera is shown by the work of HumpuHrey (6) on the 
Scitaminales. In this order HumpHrey found a progressive series 
of stages in the development of the endosperm. The Musaceae 
have a large starch bearing endosperm, in the Zingiberaceae and 
Cannaceae the endosperm is thin and contains only aleuron, while 
in the Marantaceae it is apparently not present in the mature seed. 
Variation occurs, as HUMPHREY shows, even within a single family. 
Among the Musaceae, Heliconia shows a distinct, though rather 
thin, starch bearing perisperm, while in Strelitzia only a thin layer 
of nucellar tissue showing no cellular structure remains in the 
mature seed. It is interesting to note that in the latter genus 
the massive endosperm never wholly fills the cavity of the seed, 
a condition comparable to that noted by the writer in Fagopyrum. 
YALE UNIVERSITY 
LITERATURE CITED 
1. BILLINGS, FREDERICK H., Beitrage zur Kenntnis der Samenentwickelung. 
Flora 88:253-318. 1got. 
2. CHAMBERLAIN, C. J., The ovule and female gametophyte of Dioon. Bort. 
AZ. 422321-358. 1906. 
3. Coutter, J. M., and CHamBERtany, C. J., Morphology of angiosperms. 
New York. 1903. 
4. Harz; C: os Landwirthschaftliche Samenkunde. Berlin. 1885. 
5. HorMEIsTER, W., Neuere Beobachtungen a Embryobildung der 
Psi Jahrb. Wiss. Bot. 1:82-188. 8. 
6. Humpurey, JAMEs E., oe development of ie seed in the Scitamineae. 
Ann. Botany 10: 1-37. 
7. JouNson, D. S., On a dlevelonment of certain Piperaceae. Bot. Gaz. 
34: 321-338. 1902. 
8. Juet, H. O., Die Tetradenteilungen bei Taraxacum und anderen Cichori- 
aceen. Kgl. Svenska Vet. Akad. 394:1~20. 1905. 
