318 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
tapete, dividing simultaneously from the 2-celled stage, the 3rd or 4tli 
cell becoming the definitive embryo-sac mother-cell. The nucleus of 
the archespore is peculiar in its large nucleolar-like structures. 
Chromosomes in the Development of the Pollen-grains of Allium.* * * § 
— In opposition to the statement of Ishikawa, Mr. D. M. Mottier states 
that there is no reduction in the number of chromosomes in the division 
of the archespore cells in Allium Cepa ; the division is not effected in 
the heterotypic method. The reduction takes place only in the first 
division of the pollen-mother-cells themselves. This is the case in all 
the genera of Liliacem examined. 
Protoplasmic Sac.f — Prof. E. Chodat states that, contrary to the 
general assertion, when a vegetable cell is plasmolysed, the protoplasmic 
sac does not become at once detached from the cell- wall, but always 
remains for a time attached to it by threads of hyaloplasm, often of great 
delicacy and in enormous numbers. This phenomenon has been ob- 
served not only in the parenchyme of Phanerogams, but in the prothal- 
lium and in the parenchyme of the leaf of Ferns, in Characeae, the leaves 
of Musci and Hepaticfe, and in Saprolegniacese, Vaucheria , Conjugate, 
Chaetophoraceae, and CEdogoniaceae. In many hairs these threads radiate 
in all directions, and not merely towards the base of the hair. The 
author regards this phenomenon as establishing the close connection 
which exists between the cell-wall and the protoplasm contained in it. 
(2) Other Cell-contents (including Secretions). 
Cell-wall Mucilage.^ — Herr O. Eosenberg describes the mucilage- 
tissue in the seed of Magonia glabrata (Sapindaceae), which differs but 
little from that in the leaf. In the ripe seed it exhibits pectin reactions, 
but still contains a little cellulose. It appears to serve the function of 
a storehouse of water for the use of the embryo. 
Wax as an Excretion within the Cell.§ — Prof. M. Mobius describes 
an instance of this in the case of a species of Hhus. In the ripe fruit 
of this plant, the wax-cells form a layer in contact with the resin- 
passages. In these parenchymatous cells the wax forms a thick incrus- 
tation on the cell-wall within the cell. The wax is probably a product 
of the transformation of starch. The wax-cells contain a granular 
protoplasm and a nucleus, but no or very little starch. 
(3) Structure of Tissues. 
Formation of Cork-Tissue in the Roots of the Rosaceae.|J — According 
to Dr. Martha Bunting, there are intercellular spaces between the cork- 
cells in the root of all herbaceous and shrubby species of Eosacese ex- 
amined ; but they are absent from the arborescent species. There is an 
alternation of a flattened, usually pigmented, layer of cells with 1-3 layers 
of rounded cells in each annual ring. Protoplasm, nuclei, and starch- 
grains exist in cork-zones 4-5 layers removed outside the phellogen. 
* Ber. Deutech. Bot. Gesell., xv. (1897) pp. 474-5. Cf. this Journal, 1897, p. 555. 
t Arch. Sci. Phys. et Nat., v. (1898) pp. 96-9. 
X Bih. k. Svenska vetensk. Akad. Handl., xxiii. (18 pp. and 1 pi.). See Bot. 
Centralbl., 1897 (1898), Beih., p. 345. 
§ Ber. Deutsch. Bot. Gesell., xv. (1897) pp. 425-41. 
|| Bot. Gazette, xxv. (1897) pp. 117-8. 
