ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
759 
composed of two anatomically different tissue-elements, which appear 
also to have a different physiological function so long as the shoot is in 
the bud-condition. The growing point (in the narrower sense), the 
procambial bundles, and the bud-sheath, are always destitute of chloro- 
phyll and starch while enclosed within the bud, chlorophyll being 
formed in their cells as soon as they pass out of the embryonal con- 
dition. 
Development of the Tubercles of Leguminosae.* — M. E. Gain finds 
that the humidity of the soil has a considerable influence in promoting 
the development of the tubercles of Leguminosae. The experiments 
were made on Pisum sativum , Lupinus albus, Faba vulgaris , Lotus 
corniculatus, Orobus niger, and Trifolium procumbens. 
Exudation from Leaves. — The late Prof. F. Pasquale | records the 
occurrence of the fall of a quantity of fluid in the form of small drops 
from the leaves of lime-trees. The phenomenon is in no way connected 
with the production of manna as the result of the attacks of aphides, but 
resembles the process which takes place normally in Csesalpinia pluviosa 
and some other trees. It takes place only during the period immediately 
preceding the opening of the flowers, when the vital processes are most 
active, and when the transpiration from the leaves is not sufficient to 
eliminate the whole of the water absorbed from the soil. 
M. E. Guinier f describes a similar exudation from the leaves of an 
orange-tree. 
Transpiration from Grafts. § — M. L. Daniel finds, in the case of 
herbaceous grafts, a strong formation of starch. This is the result of the 
dehydrization of sugar, transpiration taking place at the expense of sub- 
stances contained in the grafts, in consequence of a diminished flow of 
crude sap from the stock. 
(4) Chemical Changes (including Respiration and Fermentation). 
Entrance of Diastase into the Endosperm. || — Herr J. Griiss 
describes the mode in which, in the maize, the diastase-ferment is ex- 
creted from the palisade-cells of the scutellum, and thence passes into 
the tissue of the endosperm, causing the conversion of starch into 
glucose in its cells. In Dicotyledons the formation of diastase takes 
place at the point of insertion of the cotyledons, whence it advances 
gradually through the tissue. 
B. CBYPTOGAMIA. 
Cryptogamia Vascularia. 
Sporophyte of Vascular Cryptogams.lf — Prof. F. O. Bower dis- 
cusses several points in the morphology of the spore-producing members 
of the EquisetaceaB and Psilotaceae. He does not agree with Goebel’s 
statement that the archespore of Equisetum is of hypodermal origin ; the 
* Comptes Rendus, cxvi. (1893) pp. 1394-7. 
f Bull. Soc. Rot. Ital., 1893, pp. 257-61. 
j Comptes Rendus, cxvi. (1893) pp. 1001-2. § Tom. cit., pp. 763-5. 
|| Ber. Deutsch. Bot. Gesell., xi. (1893) pp. 286-92 (1 pi.). 
Proc. Roy. Soc., liii. (1893) pp. 19-23. 
