Birbal Sahni. 
25 i 
THE ANATOMY OP NEPHROLEPIS VOLUBILIS J.Sm., 
WITH REMARKS ON THE 
BIOLOGY AND MORPHOLOGY OP THE GENUS. 
By Birbal Sahni, 
Emmanuel College, Cambridge. 
[With Plate IV and Seven Figures in the Text], 
I. Introduction. 
f \HE subject of this paper is a description of a species of 
Nephrolepis ( N . volubilis J.Sm.) 1 collected near Kuala 
Lumpur, Federated Malay States, by Mr. F. T. Brooks during 1914. 
In spite of its many interesting features, this plant does not seem 
to have been previously investigated. 2 The enormously long stolons 
which enable the young plants arising on them to climb trees to a 
very considerable height, the entire absence of roots on these lateral 
plants, and the presence on them of coiled tendril-like stolons which 
suggest contact irritability, are features of biological interest which 
seemed worth investigating; the mode of branching of the stolons 
and the structure of the lateral plants were followed out in some 
detail. Unfortunately, no part of the mother-plant was available, 
nor is the latter represented in any of the specimens at the Kew 
Herbarium ; each contributor seems to have collected only a portion 
of the long stolon bearing some lateral plants. 
It may be mentioned that several of the systematic authors 
who have described this plant refer to the stolon as if it were the 
main axis of the plant. 3 I am indebted to Mr. Boodle for the 
discovery of this error. 
During the work, comparisons with other species of Nephrolepis 
were frequently necessary, and a few of these observations are 
included below. These would have been inaccessible to me had it 
not been for the kindness of Dr. Stapf, who granted me the 
privilege of dissecting dried material from the Royal Herbarium, 
1 Christ, “ Farnkrauter der Erde,” p. 288, 1897; Clarke, Trans. Linn. Soc., 
Bot. II, 1879, p. 541, pi. 78. Synonyms are N. radicans, Kuhn, Ann. Mus. Bot. 
L.B. iv., 285 ; Polypodium radicans, Burm. (oldest name). 
1 The only anatomical observations which can refer to this plant are in a 
paper (Ann. Sci. Nat. V, t. xii, 1869) by Tr^cul, called “ Remarques sur la 
position des trachees dans les Foug&res.” The author, in a footnote on p. 245, 
alludes to the outstanding anatomical features of a fern which he elsewhere 
(Ann. Sci. Nat. V. t. x, 1869, p. 351) regards as probably a Nephrolepis, but 
which he was unable to identify. His brief account, so far as it goes, agrees 
largely with that set forth below, and it is likely that his plant was the same. 
8 Clarke, l.c. ; Christ, l.c.; Diels in Engler u. Prantl, Nat. Pfl. ; van A. 
van Rosenburgh, “Malayan Ferns,” 1908, p. 161. 
