The Encyclopædia britannica; a dictionary of arts, sciences, literature and general information (1910) (14788675753)

Identifier: encyclopdiabri01chis (find matches)
Title: The Encyclopædia britannica; a dictionary of arts, sciences, literature and general information
Year: 1910 (1910s)
Authors: Chisholm, Hugh, 1866-1924
Subjects: Encyclopedias and dictionaries Encyclopedias
Publisher: Cambridge, Eng., New York : At the University press
Contributing Library: University of California Libraries
Digitizing Sponsor: Internet Archive



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surrounding thesporogenous filaments. This is a ceramidium. The attachment of the cell of an ooblastema filament to a cellof the thallus may be effected by means of a minute pore, or thetwo cells may fuse their contents into one protoplasmic mass. Inthe latter case, and especially where the union is with a specialauxiliary cell, it is of importance to know what happens to the nucleiof the fusing cells. Schmitz was of opinion that in the cases of openunion there occurred a fusion of nuclei similar to that which occurs inthe sexual union of two cells. He founded his generalization to a largeextent upon the observation that in Gtoeosiphonia capillaris two cellscompletely fuse, and that only one nucleus can be detected in thefused mass. Oltmanns has recently re-investigated the phenomenain this plant, among others, and has shown that the nucleus of thecell which is being preyed upon recedes to the wall and graduallyatrophies. The nucleus of the ooblastema filament dominates the ALGAE 593
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A. Polysiphonia sp., apical region showing leading cell and cutting off of pericentral cell. B. Polysiphonia sp., transverse section through a branch, and at a, mother-cell of tetraspores. C. Lomentaria sp., apex showing growth in length through co- ordinated growth of many filaments. D. Delesseria sp., showing apical region with leading cell. E. Chrysymenia uvaria, axis with swollen leaf-lilce appendages. F. Polyzonia sp., branch with leaf-like branches of limited growth. G. CaUithamnton sp., tetrasporangium with spores arranged in a tetrad.H. Corallina sp., tetrasporangia with zonate arrangement of tetra-spores. Fig. 5.—Rhodophyceae, variously magnified. K. Nemalion sp., carpogonial and antheridial branches. L. Batrachospermum sp., trichogyne with spcrmatia attached; carpo-spores arising from fertilized carpogonium. M. Polysiphonia sp., antheridium. N. Constantinea sp., with flattened leaf-like appendages. O. Dudresnaya coccinea, fusion of ooblastema filaments with auxil-iary cell