ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
71 
Cleistogamy in the Solanaceae." — Prof. E. Hackel records the 
occurrence of cleistogamous flowers in Salpiglossis variabilis , the first 
time it has been observed in the Solanacese. It appears to be the result 
of unfavourable nutritive conditions of the soil. 
t (2) Nutrition and Growth (includingi Germination, and Movements 
of Fluids). 
Activity of Assimilation in Leaves.-j- — Herr R. Meissner has esta- 
blished the fact that when dorsiventral leaves are inverted, the activity 
of assimilation is reduced. This is due to the closing of the stomates 
under the influence of direct sunlight, and to the chlorophyll-grains of 
the palisade-parenchyme being unable to perform their function. In 
isolateral leaves, on the other hand, no change is produced by inversion. 
The removal of the epiderm of the lower surface increases the intensity 
of assimilation. 
Correlation in the Growth of Roots and Shoots.J — Herr L. Kny 
has experimented on the effect produced by the destruction of the root 
on the growth of the stem, and the reverse, in certain seedlings and cut- 
tings. In seedlings — Zea Mays, Vicia Faba — the general result was 
that the growth of the roots and that of the shoots proceed with a high 
degree of independence, the complete destruction of the one having no 
very marked effect on the growth of the other. In cuttings — Salix acu- 
minata, S. purpurea — the results were different ; the removal of the 
shoot arresting the development of the roots ; and, to a less degree, the 
removal of the roots arresting the development of the shoot. 
Penetration of Roots into Living Tissues.§— From experiments 
made chiefly on the penetration of the roots of the pea and other plants 
into potato-tubers, Mr. G. J. Peirce concludes that the process differs in 
some respects from that in true parasites. In the latter case, the root 
of the parasite exudes a starch-corroding ferment, which is not the case 
with the former. While haustoria absorb from the hosts both organic 
and inorganic nutrient substances, true roots take up only water and 
substances dissolved in the water. The power of penetration into living 
tissues is, however, not a special property of the roots of parasites. 
Insectivorous habit of Drosophyllum.|| — Drs. A. Meyer and A. 
Dewevre have investigated the structure of the leaves of Drosophjllum 
lusitanicum, and the mode in which they capture insects. Three colla- 
teral vascular bundles run through the leaf from the base to the apex. 
These are connected with one another by smaller bundles, and from 
them all there branch off tracheal bundles which end beneath the cells 
of both the sessile and the stalked glands ; the sieve-tube bundles do 
not reach as far as the glands. The stalked glands are completely 
covered by a strong cuticle, through which the secretion oozes. The 
secretion is strongly acid, but contains neither formic nor oxalic acid, 
* SB. Yersamml. Deutsch. Naturf. u. Aerzte, 1894. See Bot. Centralbl., lx. 
(1894) p. 258. 
f Beitr. z. Kemitn. d. Assimilationsthatigkeit d. Blatter, Bonn, 1894, 48 pp. See- 
Bot. Centralbl., lx. (1894) p. 206. J Ann. Bot., viii. (1894) pp. 265-80. 
§ Bot. Ztg., lii. (1894) 2* * * § ® Abtheil., pp. 169-76 (1 fig.). 
j| Bot. Centralbl., xl. (1894) pp. 82-41 (1 fig.). 
