214 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
in favour of Van Tieghem’s that the scutellum and the coleoptile (the 
first leaf-sheath) represent two different portions — the lamina and the 
ligule— of a single cotyledon, the epiblast being an outgrowth on the 
margin of the scutellum. Hanstein has established that the coleoptile 
arises at the base of the terminal scutellum, and can therefore not be an 
independent foliar organ. The interval which frequently occurs in the 
ripe seed between the plumule which is invested by the coleoptile and 
the insertion of the scutellum is not an internode, but an elongated 
leaf-node, and the author proposes for it the term mesocotyl. In all 
Monocotyledons, therefore, with the exception of the Dioscoreaceae and 
the Commelynaceae, the single cotyledon is terminal to the embryo. 
The development of the embryo in Monocotyledons takes place in 
three different ways : — In the simplest, the lamina is the direct terminal 
prolongation of the sheath, the cotyledon assuming more or less thu 
function of a sucking organ. In the second mode, the lamina is not 
terminal to the sheath, but lateral. In the third (grasses) the lamina 
and sheath have completely lost their connection, and are separated by 
a distinct mesocotyl. In the third and fourth modes the cotyledon 
is completely modified into a sucking organ, and no longer has assimi- 
lating functions. 
The course of the vascular bundles confirms the view of a connection 
between coleoptile and scutellum. The ligule represents an axillary 
sheathing double stipule, the lamina being transformed into the scutellum 
and the ligule into the coleoptile. On a mature leaf of Oryza sativa the 
author detected a structure corresponding to the epiblast. 
Germination of Pollen-grains.* — Prof. G. Arcangeli has observed 
the length of time before germination commences in the case of the 
pollen-grains of a number of plants belonging to different natural orders. 
The nutritive medium employed was a solution of saccharose of 5, 10, or 
20 per cent., and the commencement of germination was regarded to be 
the first appearance of the protuberance caused by the germinating 
pollen-tube. The average period before germinating was from. 20 to 
30 minutes ; the pollen-grains of Canna indica required a whole 
hour. 
Pollination by Bats.f — Dr. P. Knuth gives another instance, ob- 
served by Mr. J. H. Hart in Trinidad, of the pollination of flowers by a 
bat, viz. of Eperna falcata by Glossonycteris Geoffroyi. He also calls 
attention to the fact that a similar phenomenon had been observed in 
1892 by Herr W. Burck in Java, viz. in the visits of P ter opus edulis to a 
species of Freycinetia. 
Pollination of Composite, Campanulaceae, and Lobeliaceae.J — 
Prof. B. Gerard points out the similarity in the mode of pollination in 
these nearly allied orders. The flowers are, as a rule (when hermaphro- 
dite) proterandrous. The hairs on the style do not, as is generally 
stated, perform the function of collecting the pollen for the purpose of 
self-pollination, but assist rather in its dissemination for cross-pollina- 
* Bull. Soc. Bot. Ital., 1897, pp. 26*2-6. 
t Bot. Centralbl., lxxii, (1897) pp. 353-4. Cf. this Journal, 1897, p. 309. 
X ‘ Sur la pollination chez les Composees, Campanulacees, et Lobeliace'es,’ .Lyon,. 
1897, 11 pp. See Bull. Soc. Bot. France, xliv. (1897) Rev. Bibl., p. 408. 
