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 198 PttOTOZOA. mation. The buds separate themselves from the membrane and become free as small spores, with nucleus and cylindrical appendage, to assume the Noctiluca form under circumstances which have as yet not been closely observed. According to Cienkowski, conjugation may take place between normal forms as well as between encysted forms. The Noctiluca owe their name to their power of producing light. —a power whic
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 198 PttOTOZOA. mation. The buds separate themselves from the membrane and become free as small spores, with nucleus and cylindrical appendage, to assume the Noctiluca form under circumstances which have as yet not been closely observed. According to Cienkowski, conjugation may take place between normal forms as well as between encysted forms. The Noctiluca owe their name to their power of producing light. —a power which they share with numerous sea animals, such ;is Medusa?, Pyrosoma, etc. The light proceeds from the peripheral layer of protoplasm. Under certain conditions they rise from the; deep to the surface of the sea in such enor- mous numbers as to cause wide tracts of the sea to give out a reddish light. It is after sunset, and especially in the evening, when the sky is overcast, that we get the beautiful phenomenon of the phosphorescent sea. The species distributed in the North Sea and in the Atlantic Ocean is Noctiluca ;iiiliaris. Nearly allied is the Mediterranean Leptodiscus medusoides R. Hertwig. Order 2.—CILIATA.* Ciliated Infusoria u-itk mouth and anus, sarcode body of complicated structure (ivitJi endoplasm and exojdasm}, with nucleus and paranucleus (iiucleolus). .... The locomotive cuticular appendages that FIG. lo/.—Stylowycn a i>it/ti,u., Ad oral .,. , . , f, ,1 •, •, f ? zone of cilia; C, contractile ^llla> wlllch °ften COVCr the wll°le SU1>faCe °f vacuoie; N, nucleus; J\'', the body in close rows, and give it a striped paranucleus; A, anus. m, ... ,, appearance. The cilia are usually stronger in the region of the mouth, and are here grouped so as to form an adoral zone of large cilia, which, during swimming, causes a whirl- pool, and conducts the matter which serves as nourishment into the mouth (fig. 137). This adoral zone is more highly developed
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