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Labyrinthulidea
1911 Encyclopedia Britannica
or the name given by Sir Ray Lankester (1885) to Sarcodina forming a reticulate plasmodium, the denser masses united by fine pseudopodical threads, hardly distinct from some Proteomyxa, such as Archerina. This is a small and heterogeneous group. Labyrinthula, discovered by L. Cienkowsky, forms a network of relatively stiff threads on which are scattered large spindle-shaped enlargements, each representing an amoeba, with a single nucleus. The threads are pseudopods, very slowly emitted and withdrawn. The amoebae multiply by fission in the active state. The nearest approach to a "reproductive" state is the approximation of the amoebae, and their separate encystment in an irregular heap, Labyrinthulidea.
2. A colony or "cell-heap" of 1. A colony or "cell-heap" of crawling upon an Alga.
Labyrinthula vitellina, Cienk., oides, Archer, with fully ex Chlamydomyxa labyrinthul- their definite spindle-shaped several cells which have lost contour. s, Corpuscles which about to be encysted).
have become spherical and are no longer moving (perhaps panded network of threads 4. A single spindle cell and threads on which the oat-shaped of Labyrinthula macrocystis, corpuscles (cells) are moving. Cienk. n, Nucleus.
o, Is an ingested food particle; 5. A group of encysted cells of L. at c a portion of the general Macrocystis, embedded in a protoplasm has detached ittough secretion.
self and become encysted. 6, 7. Encysted cells of L. macro- 3. A portion of the network of cystis, with enclosed proto Labyrinthula vitellina, Cienk., plasm divided into four spores. more highly magnified. p, Pr08, 9. Transverse division of a non toplasmic mass apparently encysted spindle-cell of L. produced by fusion of several macrocystis. filaments. p', Fusion of v? . ? ¦ recalling the Acrasieae. From each cyst ultimately emerges a single amoebae, or more rarely four (figs. 6, 7). The saprophyte Diplophrys (?) stercorea (Cienk.) appears closely allied to this.
Chlamydomyxa (W. Archer) resembles Labyrinthula in its freely branched plasmodium, but contains yellowish chromatophores, and minute oval vesicles ("physodes") filled with a substance allied to tannin - possibly phloroglucin - which glide along the plasmodial tracks. The cell-body contains numerous nuclei; but in its active state is not resolvable into distinct oval amoeboids. It is amphitrophic, ingesting and digesting other Protista, as well as "assimilating" by its chromatophores, the product being oil, not starch. The whole body may form a laminated cellulose resting cyst, from which it may only temporarily emerge (fig. 2), or it may undergo resolution into nucleate cells which then encyst, and become multinucleate before rupturing the cyst afresh.
Leydenia (F. Schaudinn) is a parasite in malignant diseases of the pleura. The pseudopodia of adjoining cells unite to form a network; but its affinities seem to such social naked Foraminifera as Mikrogromia. See Cienkowsky, Archiv f. Microscopische Anatomie, iii. 274 (1867), xii. 44 (1876); W. Archer, Quart. Jour. Microscopic Science, xv. 107 (1875); E. R. Lankester, Ibid., xxxix., 233 (1896); Hieronymus and Jenkinson, Ibid., xlii. 89 (1899); W. Zopf, Beitrcige zur Physiologie and Morphologie niederer Organismen, ii. 36 (1892), iv. 60 (1894); Penard, Archiv fiir Protistenkunde, iv. 296 (1904); F. Schaudinn and Leyden, Sitzungsberichte der KOniglich preussischen Akademie der Wissenschaft, vi. (1896).
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Chisholm, Hugh, General Editor. Entry for 'Labyrinthulidea'. 1911 Encyclopedia Britanica. https://www.studylight.org/encyclopedias/eng/bri/l/labyrinthulidea.html. 1910.
