. The British freshwater Rhizopoda and Heliozoa. Fig. 13.—Early stage in the conjugation of Difflugia pyriformis,var. lacustris: two individuals approaching each other, theplasma of the one enveloping the oral aperture of the other,and the granular substance of the two animals few minutes sufficed to bring the mouths of the tests closetogether. x 200. The cysts, so commonly observed in the testaceousRhizopoda {NeheJa, Difflugia, Enghjjylia, etc.) protectwhat are known as swarm-spores. The parentorganism splits up into separate cells, each cell pro-vided with its portion of the nu
. The British freshwater Rhizopoda and Heliozoa. Fig. 13.—Early stage in the conjugation of Difflugia pyriformis,var. lacustris: two individuals approaching each other, theplasma of the one enveloping the oral aperture of the other,and the granular substance of the two animals few minutes sufficed to bring the mouths of the tests closetogether. x 200. The cysts, so commonly observed in the testaceousRhizopoda {NeheJa, Difflugia, Enghjjylia, etc.) protectwhat are known as swarm-spores. The parentorganism splits up into separate cells, each cell pro-vided with its portion of the nucleus, and also, onliberation, with means of locomotion, which may be. Fie. 14.—Late stage in the conjvigation of Nebela collaris: twotests closely adhering, one filled with protoplasm, the othernearly empty. In the latter the remaining protoplasm con-tinued to be attached to its test by numerous protoplasmicthreads. x 250. flagella or pseudopodia. These either undergo subse-quent fission or develop at once into the typical form. Bncistment is probably preceded by the conjugation(copulation, Blochmann) of two individuals. It hasbeen observed in many testaceous forms. Individualsin pairs, having the mouths of their tests closely 26 KEITISH FRESHWATER RHIZOPODA. adhering, are of frequent occurrence. Where the testsare sufficiently transparent, a streaming of the proto-plasm may be observed from one shell into the other((. (J. Euglijpha, Giipltotleria), slow but continuous, untilone shell is entirely emptied. The pair will remainattached for a considerable time, and it is presumedthat after separation the encistment of the unitedprotoplasm, in the test wh
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