ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 
755 
In Clematis balearica and cirrhosa the ordinary thin dividing wall of 
two cells is widened to a wedge-shaped structure which reaches to the 
inner walls and shows the reactions of cutin. Pluricellular triehomes 
are especially characteristic of the genus Thalictrum. Vascular bundles 
are frequently found in the medullary tissue of the leaf-stalk. Crystals 
of calcium oxalate very rarely occur in the leaves. 
Pitchers of Dischidia. — Three species of Dischidia (Asclepiadese) 
produce pitchers. Mr. P. Groom * * * § describes in detail the structure 
and functions of those of D. Bafflesiana , a twining epiphyte found 
chiefly on decaying trees at Singapore. The author confirms in the 
main Treub’s view that they are not adapted for the capture of ants or 
other insects, and that their chief purpose is the storage of water. 
Living and dead insects are, however, found abundantly in the pitchers ; 
and the detritus formed by them and by the substances which they bring 
is probably utilized in the nutrition of the plant, being absorbed by 
adventitious roots formed within the pitchers. 
The pitchers are leaves modified for the purpose of providing shelter 
for ants and for accommodating the materials brought by them, and 
for the storage of rain-water and of the substances brought down 
with it. 
Dr. D. H. Scott and Miss E. Sargant^f have arrived at the same 
general conclusions with regard to the function of the pitchers of Dis- 
cliidia Bafflesiana. The inside of the pitchers is coloured a deep purple 
due to a soluble pigment which is limited to a thin layer of the meso- 
phyll next the inner surface. Besides unicellular glandular hairs which 
secrete mucilage, the plant bears secretory emergences in three posi- 
tions, petiolar, laminar, and apical ; they secrete mucilage, and are 
neither carnivorous nor myrmecophilous. The structure of the adven- 
titious roots, which presents some anomalies, is described in detail. 
Bud-protection in Dicotyledons.^ — Mr. P. Groom describes the 
mode in which the young buds are protected by colleters in plants 
belonging to the natural orders Rubiaceae, Apocynacese, Asclepiadem, 
Guttiferae, and Dilleniaceae. These villous colleters are by no means 
always triehomes, but are frequently emergences, as is shown by their 
being penetrated by laticiferous tubes or vascular bundles. They are 
apparently not only protective, but also excretory. In some cases the 
secretion passes through the cuticle. The villi contain transitory starch, 
raphides or sphero-crystals, colouring matters, and tannins. 
Winter-buds of TJtricularia.§ — Mr. J. M. Holzinger describes the 
winter buds or “ hibernacula ” of Utricularia intermedia. They consist 
of numerous broadly palmate scales crowded along a short axis and 
furnished along the margin with tufts of bristles ; these scales appear 
to be metamorphosed leaves. 
Rhizome of Corallorhiza.||— Mr. M. B. Thomas describes the struc- 
ture of the coral-like rhizome of Corallorhiza (chiefly innata and multi- 
* Ann. Bot., vii. (1893) pp. 223-42 (1 pi.), and Proc. Roy. Soc., liii. (1893) 
pp. 51-2. f Ann. Bot., vii. (1893) pp. 243-68 (2 pis. and 3 figs.). 
% Trans. Linn. Soc., iii. (1893) pp. 255-66 (2 pis. and 1 fig.). 
§ Bull. Torrey Bot. Club, xx. (1893) pp. 288-90 (1 pi.). 
j| Bot. Gazette, xviii. (1893) pp. 166-70 (2 pis.). 
