Pearson.—On the Embryo of Welwitschia. 
765 
Summary. 
1. The intraseminal development of the embryo is continuous, and 
is apparently completed before the seed falls. It occupies not more than 
four months from the time of fertilization. 
2. A few terminal initial cells (Figs. 1, 2, 6, 7) are replaced by a single 
massive meristematic group (Fig. 3) which in due course gives rise to 
distinct root and stem growing points (Fig. 4). 
3. The £ lateral cones ’ are visible as small protuberances in the axils of 
the cotyledons in the embryo of the seed. 
4. The suspensor becomes greatly increased in thickness by centrifugal 
additions formed, as in Ephedra , in acropetal succession from superficial 
cells of the root-cap. The later formed of these usually show a degree 
of independence of the rest of the suspensor in the direction of their growth, 
and it may be that they are specially adapted to the function of absorption. 
5. In intermediate stages the ovules are frequently polyembryonic, 
owing to the branching of the embryonic mass. 
6. So far as is known the mature seed never contains more than one 
embryo. 
7. Two seeds collected in Damaraland in January, 1907, germinated 
readily in April, 1910. 
Botanical Laboratory, 
South African College, 
Cape Town. 
Literature cited. 
Bower, F. O., 1881 : On the further development of Welwitschia mirabilis. Q.J.M.S. xxi (N.S.), 
P- 57 1 * 
-, 1882 : The Germination and Embryology of Gnetum Gnemon. 1 . c. xxii (N.S.), 
p. 278. 
Henriques, J., 1910 : Welwitschia mirabilis. Gardeners’ Chronicle, April 2, 1910. 
Hooker, J. D., 1863 : On Welwitschia , a new genus of Gnetacese. Linn. Soc. Lond. Trans., 
xxiv, p. 1. 
Land, W. J. G., 1907 : Fertilization and Embryogeny in Ephedra trifurca. Botanical Gazette, 
xliv. 273. 
Pearson, H. H. W., 1906 : Some Observations on Welwitschia mirabilis , Hook. fil. Phil. Trans. 
Roy. Soc. B. 198, p. 265. 
- 1907 : The Living Welwitschia. Nature, April 4, 1907. 
-- 1909 (a) : Further Observations on Welwitschia. Phil. Trans. Roy. Soc. B. 
200, p. 331. 
- 1909 (b) : Percy Sladen Memorial Expedition in South-West Africa, 1908-9, ii. 
Nature, October 21, 1909. 
Strasburger, E., 1879 : Die Angiospermen und die Gymnospermen. Jena. 
