EVOLUTIONARY STATUS OF POLYCOTYLEDONY 
119 
The primitive gymnosperm embryo had numerous cotyledons, which were 
imperfectly cyclic and variable in number. These cyclic cotyledons were 
in all probability derived from spirally arranged leaves that became cyclic 
in the cotyledonary node. Cotyledonary fusions reduced the mumber of 
cotyledons and also produced cotyledonary tubes in many species. Di- 
cotyledony was attained either by a general fusion of many cotyledons in 
two groups, or by an extremely bilabiate development of a cotyledonary 
tube; and monocotyledony is the result of a cotyledonary tube becoming 
unilabiate in the course of its development. The polycotyledonous con- 
dition is therefore primitive and the dicotyledonous one is derived. 
West Texas State Normal College, 
Canyon, Texas 
LITERATURE CITED 
1. Angela, Sister Helen. Coulter and Chamberlain's Morphology of gymnosperms, chap. 
9, pp. 427-430. Chicago, 1910. 
2. Buchholz, John T. Suspensor and early embryo of Pinus. Bot, Gaz. 66: 185-228. pis, 
VI-X, figs. 3. 1918. 
3. Coulter, John M. The origin of monocotyledony. Annals Mo. Bot. Card. 2: 175-183. 
figs. 9. 1915. 
4. Coulter, John M., and Land, W. J. G. The origin of monocotyledony. Bot. Gaz. 57: 
509-519. 1914. 
5. Coulter, John M., and Chamberlain, C. J. Morphology of gymnosperms. Chicago, 
1910. 
6. Hill, T. G., and DeFraine, E. On the seedling structures of gymnosperms I. Annals of 
Botany 22: 689-712. figs. 8. 1908; II. Op. cit. 23: 189-227. pi. 15, figs. 11. 1909; 
III. Op. cit. 23: 433-458. pi. 30. 1909; IV. Gnetales. Op. cit. 24: 319-333. pis. 22- 
23. 1910. 
7. Hutchinson, A. H. Morphology of Keteleeria Fortunii. Bot. Gaz. 63: 124-135. pis. 
7-8. 1917. 
8. Jeffrey, E. C. The anatomy of woody plants. Chicago, 19 17. 
