Elementary text-book of zoology, tr Elementary text-book of zoology, tr. and ed. by Adam Sedgwick, with the assistance of F. G. Heathcote elementarytextbo01clau Year: 1892-1893 REPRODUCTION OF CILIATA. 201 to the shape of a horse-shoe or a band, and may be broken up into a number of fragments. It contains a granular viscid substance, is bounded by a delicate membrane, and, a b according to the erroneous views of Stein and Balbiani, gives rise to ova or to germi- nal spores. The nucleolus or paranucleus also varies in form, position, and number in different species. It is always much smaller t
Elementary text-book of zoology, tr Elementary text-book of zoology, tr. and ed. by Adam Sedgwick, with the assistance of F. G. Heathcote elementarytextbo01clau Year: 1892-1893 REPRODUCTION OF CILIATA. 201 to the shape of a horse-shoe or a band, and may be broken up into a number of fragments. It contains a granular viscid substance, is bounded by a delicate membrane, and, a b according to the erroneous views of Stein and Balbiani, gives rise to ova or to germi- nal spores. The nucleolus or paranucleus also varies in form, position, and number in different species. It is always much smaller than the nucleus, and is strongly refractile; it usually lies close to the nucleus, or even sunk in a cavity of the latter. Both play an important part in the reproduction of the Infusoria. The most usual method of reproduction in the Infusoria is by fission. When the forms reproduced remain together and connected with the parent, a colony of Infusoria is formed, , the stocks of Epistylis and Carchesium. Fission usually takes place by a trans- verse division (at right angles to the long axis), as in the Oxytrichidce, FIG. 141.—a, Asp'ullsca Ij/ncaster (afterStein). b,Aspidiscapolyity- la, during fission (after Stein).
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