46 
T. G. Hill. 
lead to an injurious accumulation of salt in the plant. Other 
theories have been suggested or discussed by different authors, e.g. 
Stahl, Diels and Benecke. 1 
These need not be entered into here, but in view of the fact 
that all halophytes show xerophytic characters of some kind, it 
appears that these characters are either necessary to existence in a 
maritime situation or are the natural result of a halophilous mode 
of life. As one such character, namely succulence, may be directly 
induced by treatment with salt, it may be suggested that, in certain 
cases of an inland form spreading to a maritime situation, this 
character may have been directly produced in the first instance by 
the action of salt, and may afterwards have become fixed 2 by the 
adaptive selection of other characters (physiological and structural), 
which cause succulent development apart from the action of salt. 
1 Stahl, Einige Versuclie iiber Transpiration n. Assimilation, 
Botan. Zeitung, Bd. 52, Abt, 1, 1894, p. 117; Diels, Stoff- 
wechsel u. Struktur d. Halophyten, Pringslieim Jahrb., Bd. 
32 (1898) ; Benecke, Ueber die Diels’sche Lehre von d. 
Entchlorung d. Halophyten, Pringslieim Jalirb., Bd. 36, 
p. 179. 
2 Some succulent maritime plants retain their succulence, 
when cultivated without salt, others form thinner leaves 
under these conditions; I.esage, Revue Generale de Bot., 
1890, p. 56. 
THE SEEDLING-STRUCTURE OF CERTAIN 
PIPERACEAE. 
By T. G. Hill. 
HE present preliminary communication deals with the transition- 
region between root and stem of Piper cornifoliutn, H. B. K. 
and Pcperomia maculosa , Hook. Notwithstanding the fact that 
these genera are closely allied, there are considerable differences in 
the behaviour of the structures concerned, and the transition in 
both plants is of a type which does not appear to have been hitherto 
described. 
Piper cornifolium. Running longitudinally through each 
cotyledon there is one bundle, which, near the base of the seed-leaf, 
bifurcates and each half revolves in such a manner that the centrally 
placed xylem becomes bounded on each side by a group of phloem 
