ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
871 
flowers ( Aconitum , Dictamnus, Delphinium) is the result of geotropism 
only without the co-operation of epinasty. The slight natural curvature 
of the upper portion of the stalk is, on the other hand, due to epinasty. 
Intertwining of Tendrils.* * * § — In opposition to the statement of 
Darwin, Mr. D. T. McDougal finds that the tendrils of Micrampelis 
echinata ( Echinocystis lobata) display no lack of sensitiveness of con- 
tact to tendrils of the same plant as contrasted with foreign bodies. 
In this respect this species agrees with other climbing plants, which 
have not developed the contact sensitiveness in such a manner as to 
be able to distinguish portions of their own or of an allied plant 
from foreign objects. 
Heliotropism of the Mallow.f— Prof. B. D. Halsted states that in 
the two common American mallows, Malva borealis and rotundifolia , the 
leaves are heliotropic. In the morning, if the day is clear, the leaves 
are placed with their upper surface at right angles to the rays of the sun, 
and, by slowly turning, this position is maintained throughout the day. 
The leaves of Gossypium are also heliotropic. 
(4) Chemical Changes (including Respiration and Fermentation). 
Pood of Green Plants.J — Reviewing the results of recent researches 
on the chemical processes which take place during the nutrition of 
plants, Mr. C. R. Barnes proposes to classify these processes under three 
heads, viz. : — (1) Photo-syntax , or the synthesis of carbon compounds 
out of carbon dioxide in the presence of chlorophyll, under the action of 
light : (2) Digestion, or the chemical change and solution of the solid 
foods; this is due in large measure, perhaps entirely, to the action of 
alterative enzymes: (3) Assimilation, or the conversion of the food 
into the living or mechanical substances of the plant tissues for repair 
of waste and growth. The author adopts the view that complex carbon 
compounds arise by condensation of formic aldehyde, and that these 
substances need not necessarily pass through the condition of starch. 
Causes of the Disappearance of Reserve Pood-materials from 
Seeds. § — According to Prof. W. Pfeffer, experiments carried on by 
B. Hansteen show that the transformation of starch into sugar in the 
endosperm is largely dependent on the rapidity with which the glucose 
is carried away. The presence of diastase is not essential to this trans- 
formation, although the scutellum has the power of producing this 
secretion. The mucilage-layer takes no part in the process. The 
absorption of reserve-cellulose and the disappearance of proteinaceous 
substances are effected in the same way as the transformation of starch. 
Respiration of Green and Etiolated Leaves. || — As the result of a 
series of experiments made chiefly on Vicia Faba , Lupinus luteus , and 
Triticum vulgare, M. W. Palladine states that, if etiolated leaves are rich 
in carbohydrates, they develope well; but if not, they remain in a rudi- 
mentary condition, notwithstanding that they may contain a large 
* Bot. Gazette, xviii. (1893) pp. 396-7. Cf. this Journal, 1893, p. 660. 
t Bull. Torrey Bot. Club, xx. (1893) pp. 489-90. 
X Bot. Gazette, xviii. (1893) pp. 403— 1 i. 
§ Ber. K. Sachs. Gesell. Wiss., 1893, pp. 421-8. 
|| Rev. Gen. de Bot. (Bonnier), v. (1893) pp. 449-73. 
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