348 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
BOTANY. 
A. GENERAL, including th.e Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
Q) Cell-structure and Protoplasm. 
Encasing of Protoplasm."^ — Herr G. Haberlandt describes the pro- 
cess of “ encasing ” (Einkapselung) of the protoplasm in the hairs of 
various CucurbitaceaB. 
In the short stiff hairs on older leaves of Bryonia the protoplasm is 
frequently divided into two parts of nearly equal size by the secondary 
thickening of the cell-wall ; one-half of the mass of protoplasm contains 
the nucleus, while the other is destitute of nucleus. If the formation 
of cellulose-wall proceeds, only that portion of the protoplasm which 
contains the nucleus forms new cell-walls. If the secondary ring of 
cellulose becomes only so thick that the protoplasm is merely deeply 
constricted, then again it is only the half of the protoplasm that contains 
the nucleus which becomes encased, the first cellulose-cap passing through 
the narrow piece which unites the two halves. Even when the free 
outer wall of the hair-cell is uniformly thickened, a division of the 
protoplasm may take place into two usually unequal halves, the portion 
which contains the nucleus becoming invested by a number of caps, one 
within another, as Krabbe has described in the bast-cells of the 
Asclepiadeje and Apocynacem.l 
A similar phenomenon is presented by the hairs on the under side 
of the leaves of Sicyos angulatus and Momordica Elaterium. The en- 
casing does not depend on the size of that portion of the protoplasm, but 
entirely on the presence of the nucleus. The phenomenon differs only 
from that mentioned above in bast-cells in the latter containing several 
nuclei, each of which becomes invested with cellulose. 
Aggregation of Protoplasm.^ — Herr T. Bokorny has confirmed 
Darwin’s statements as to the aggregation of protoplasm in the tentacles 
of Droscra by a very minute quantity of ammonia, obtaining similar 
results in a large number of different plants. The phenomena may be 
of four kinds : — contraction of the entire protoplasm ; contraction and 
division of the vacuole-wall alone ; aggregation of the protoplasmic 
albumen, i. e. excretion of granules of albumen from the cell-sap ; or 
aggregation of the albumen which is sometimes contained in the vacuole- 
fluid. The plants and parts of plants in which these phenomena were 
observed are : — Spirogyra, tentacles of Drosera rotundifolia and dichotoma, 
petals of TuUpa suaveolens, epidermal cells of the leaf-stalk or flow^er- 
stalk of Primula sinensis, stigma of Crocus vernus, hypodermal cells of 
the leaves of Cotyledon coccinea, epidermal cells of the pitcher of 
Nepenthes phyllamphora, Darlingtonia californica, and Sarracenia pur- 
purea, glandular hairs of Pelargonium, epidermal cells of the leaf of 
* SB. Akad. Wiss. Wien, xcviii. (1889) 10 pp. and 1 pi. See Bot. Ccntralbl., xl. 
(1889) p. 144. t Cf. this Journal, 1888, p. 441. 
J Jahrb. f. Wiss. Bot. (Priiigslieim), xx. (1889) pp. 427-74 (1 pi.). 
