60 
Dusuin NatTuRAL-History Society. 
Friday, January 18, 1854.—Robert Callwell, Esq., M.R.I.A., in 
the chair. 
Donations. 
Donations were announced from James R. Dombrain, Esq., and 
Mr. F fennel. 
Adventitious Roots of Jussiea grandiflora. 
Professor Allmann stated some observations he had made on a 
remarkable peculiarity of the adventitious roots of Jussiza grandi- 
flora. The author described a remarkable condition which he had 
observed in some of the adventitious roots of a specimen of this plant 
growing in the College Botanical Gardens. Some of the roots, which 
proceed from the nodes of the stem, instead of growing downwards, so 
as to fasten themselves in the mud at the bottom of the water in which 
the plant grows, assume an ascending direction, and grow into the 
air, where they present a very remarkable appearance, looking like 
portions of rush-pith attached to the stem of the plant. When exa- 
mined by the microscope, they are found to have a central, slightly 
_ developed, woody axis, round which is a peculiar structure, formed of 
exceedingly delicate stellate cells, having between them large inter- 
cellular spaces, and constituting one of the most regular and beauti- 
ful examples of a system of air-chambers to be found, perhaps, in the 
whole vegetable kingdom. A singular fact connected with these air- 
chambers is, that they are not surrounded by any epidermal invest- 
ment, but open directly into the external air. Professor Allmann also 
mentioned his discovery of a remarkable peculiarity of the woody 
fibres of the same plant; namely, the fact of these fibres being filled 
with starch granules, a condition of prosenchymatous tissue almost 
unique in the vegetable kingdom. 
THE PHYTOLOGICAL CLUB, 
(In connexion with the Pharmaceutical Society.) 
December 5th, 1853.—Robert Bentley, Esq., F.L.S., A.K.C., &c., 
President, in the chair. 
