ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
331 
Relation between Calcium and the Conduction of Carbohydrates.* * * § 
— From experiments made chiefly with Elodea canadensis and Oxalis 
floribunda, Mr. P. Groom concludes that acid potassic oxalate retards 
the action of diastase on starch, and that the main function of calcium 
is to prevent an accumulation of this salt. 
y. General. 
Galls.f — M. M. Molliard has studied the galls produced by insects 
or fungi in flowers, especially in relation to the anatomical disturbances 
brought about in the host-plant. When the same parasite attacks allied 
species, the results will often be different in the two cases. In the 
vegetative organs of the flower, either the nature or the distribution of 
the tissues may be altered. In the sexual organs, castration either of 
the pollen-sacs or of the ovules is not uncommon. A very large number 
of the various modifications of the flower caused by the attacks of 
parasites are described in detail. 
Action of Light on the Disengagement of Perfumes.^ — According 
to M. E. Mesnard, the disengagement of odours which results from the 
transformation and destruction of the substances that cause the odours 
is due to the combined action of oxygen and of light; but the latter 
is by far the most important agent. Its action is both chemical and 
mechanical. The apparatus for measuring the intensity of the perfumes 
is described in detail, as well as the results of the experiments on a 
great variety of different perfumes. 
B. CRYPTQGAMIA. 
Cryptogamia Vascularia. 
Ligule of Selaginella.§ — Prof. R. J. Harvey Gibson describes the 
structure and development of the mature ligule in a number of species 
of Selaginella. It is sunk in the tissue of the leaf-base by a more or less 
massive glossopode, bearing an intimate relation to the cells of the leaf- 
base. It has always a multicellular origin. The author agrees with 
Hofmeister rather than with Pfeffer in stating that it originates inva- 
riably from two rows of cells. With regard to its function, he regards 
it as a specialised ramentum similar to those of the Pteridophyta and of 
the Hepaticse ; its function is probably a temporary one, serving to keep 
the growing point and the young leaves moist. 
Sporophyte of the Ophioglossaceae.|| — Prof. F. O. Bower gives 
further examples, from an examination of different species of Ophio- 
glossum , Botrychium, and Helminthostachys, of various stages of septation 
in the sporange, which throw light on the affinities of the different 
families of Vascular Cryptogams. 
* Ann. Bot., x. (1896) pp. 91-6. 
f Ann. Sci. Nat. (Bot.), i. (1895) pp. 67-245 (12 pis.). 
% Comptes Eendus, cxxii. (1896) pp. 491-3 ; Rev. Gen. de Bot. (Bonnier), viii. 
(1896) pp. 129-57, 203-16 (1 pi. and 14 figs.). Cf. this Journal, 1893, p. 214. 
§ Ann. Bot., x. (1896) pp. 77-88 (1 pi.). Cf. this Journal, 1894, p. 595. 
|| Proc. Roy. Soc., lix. (1896) pp. J 37-41; Ann.*Bot., x. (1896) pp. 100-5. Cf. 
this Journal, 1895, p. 551. 
