90 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
BOTANY. 
A. GENERAL, including the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
(1)1 Cell-structure and Protoplasm. 
Structure of Cytoplasm.* — From his investigation of the phenomena 
of nuclear division in Fucus,f Prof. E. Strasburger came to the conclu- 
sion that there is a difference in structure between the kinoplasm and 
trophoplasm when in an active condition. He now gives it as a general 
law that active kinoplasm has a filamentous, active trophoplasm a honey- 
comb structure. This difference does not, however, extend to the two 
kinds of plasm when in an inactive condition ; the whole of the cyto- 
plasm having then a honeycomb structure. It is difficult to determine 
how the kinoplasm is then distributed within the walls of the network. 
In animals, on the other hand, kinoplasm or archiplasm can often he 
detected in resting nuclei. 
The centrosomes which are a constituent part of the cell in Thallo- 
phytes and Bryophytes, have not at present been detected in Pterido- 
phytes or Phanerogams. The author concludes that in these higher 
branches of the vegetable kingdom the filamentous framework of the 
kinoplasm reaches a degree of development which renders possible some 
other mode of origin of the spindle ; and this is connected with the 
special use of the combining-threads in the completion of cell-division. 
Continuity of Protoplasm in Guard-cells and Moss-leaves4 — Herr 
F. G. Kohl calls attention to the fact that in the great majority of plants 
the starch disappears in the autumn from the guard-cells of the stomates, 
while the remaining cell-contents have also either disappeared or become 
disorganised. This takes place to a large extent even in those leaves 
which remain green in the autumn. This has been supposed hitherto 
to be associated with a complete absence of protoplasmic communications 
in the guard-cells. The author shows, however, that this anomaly does 
not exist. By using the iodine-sulphuric-acid-methyl-violet method, he 
has established the presence, in very large numbers, of connecting- 
threads between the guard-cells and adjoining cells, in the mistletoe. 
In the cortical parenchyme-cells of the same plant he reckons the 
number of connecting protoplasm-threads from each cell to amount to 
from 7350 to 9600 ; in the guard-cells of the stomates they are pro- 
bably somewhat fewer. In the leaves of Catharinea undulata and other 
mosses, Herr Kohl has demonstrated the existence of similar connecting- 
threads, though in somewhat smaller numbers. He concludes that all 
the living cells of a plant are in this way united into a connected whole ; 
the most important functions of this connected system being the trans- 
port of food-materials and the conduction of irritations. 
Nuclear Division in Pollen-mother-cells. — Herr D. M. Mottier§ 
has studied the mode of division of the nucleus in the pollen-mother- 
* Jahrb. f. wiss. Bot. (Pfeffer u. Strasburger), xxx. (1897) pp. 375-405 (2 figs.). 
t Cf. infra , p. 107. 1 Bot. Centralbl., Ixxii. (1897) pp. 257-65 (1 pi.). 
§ Jahrb. f. wiss. Bot. (Pfeffer u. Strasburger), xxx. (1897) pp. 169-204 (3 pis.). 
