Studies in the Morphology of Selaginella pumila, Spring. 
211 
fig. 25. The base is surrounded by a well-developed group of reticulate 
tracheides which is usually continuous with the transfusion elements already 
described (figs. 24, 26). 
BIBLIOGRAPHY. 
*(1) Bruchmann, H. — Untersuchungen iiber Selaginella spinulosa, A. Br., Gotha, 1897. 
*(2) Bruchmann, " Von den Vegetations organen der Selaginella Lyallii," Flora, 1909. 
*(3) Bruchmann, " Selaginella preissiana," Flora, 1910. 
(Review of this paper in Bot. Gaz., 49, 399.) 
(4) Goebel, K. — Organography of Plants. 
(5) Harvey- Gibson, R. J.- — " Contributions towards a Knowledge of the Anatomy of 
the Genus Selaginella, Spr." 
Part 1. " The Stem," Ann. Bot., 8, 1894. 
Part 2. " The Ligule," Ann. Bot., 10, 1896. 
Part 3. " The Leaf," Ann. Bot., 11, 1897. 
Part 4. " The Root," Ann. Bot., 16, 1902. 
(6) Hieronymtjs. — Naturliche Pnanzen Familien., 1902. 
(7) Hill, T. G. — " On the Presence of Parichnos in Recent Plants," Ann. Bot., 20. 
(8) Lotsy, J. P. — Vortrage iiber Botanische Stammesgeschichte. 
(9) Marloth. — Flora of South Africa, Vol. I. 
(10) Sclechtendal. — Adumbriationes Plantarum, 1825. 
(11) Scott, D. H. — Studies in Fossil Botany, Part 1. 
(12) Scott, D. H., and T. G. Hill.— "The Structure of Isoetes Hystrix" Ann. Bot., 14. 
(13) Seward, A. C— Fossil Plants, Vol. II. 
(14) Sim, T. R.— Ferns of South Africa, 1915. 
(15) Sykes, M. G., and W. Stiles. — " The Cones of the Genus Selaginella," Ann. Bot., 
1910. 
(16) Uphof, J. C. Th. — "Contributions towards a Knowledge of the Anatomy of the 
Genus Selaginella : The Root," Ann. Bot., 34, 1920. 
EXPLANATION OF FIGURES. 
Fig. 1. Variations in leaf form ; from one plant. 
Fig. 2. Abnormal leaf forms. 
Fig. 3. Development of first roots at base of hypocotyl of sporeling. 
Fig. 4. Plant with unbranched stem and three roots at base of hypocotyl. 
Fig. 5, a-d. Development of first secondary axis with its root, midway between bases 
of cotyledons. 
Fig. 6. Plant with five secondary axes developed at base. a. Hypocotyl shown. 
6. Reverse of fig. a. 
Fig. 7, b. Group of secondary axes removed from primary axis a. 
Fig. 8. Part of radially symmetric stem with four leaf rows. 
Fig. 9. Cotyledons and succeeding leaf -pair cleared in caustic potash. 
Fig. 10. Part of stem with three leaf -pairs, one whorl of three leaves, and two alternate 
leaves. 
* I have had no opportunity of consulting papers (1) to (3). 
