. Elementary text-book of zoology, general part and special part: protozoa to insecta. Animals. C(ELENTERATA. 209 the parasitic animals from various wood-lice and Crustacea, which wore assij^ned by Cienkowski to the fungi, under the name uf AiiKxhidhnii j^ai'asltivum, remind us by their reproduction no less of the Gregarinas and a their cysts. The Coccidia which we meet with in the cells of the epithelium of the intes- tine as well as in the bilc- ducts of Mammalia should also be regarded as Greija- rina- (fig. 151). They trans- form themselves into egg- shaped zoosperms by the formation of a
. Elementary text-book of zoology, general part and special part: protozoa to insecta. Animals. C(ELENTERATA. 209 the parasitic animals from various wood-lice and Crustacea, which wore assij^ned by Cienkowski to the fungi, under the name uf AiiKxhidhnii j^ai'asltivum, remind us by their reproduction no less of the Gregarinas and a their cysts. The Coccidia which we meet with in the cells of the epithelium of the intes- tine as well as in the bilc- ducts of Mammalia should also be regarded as Greija- rina- (fig. 151). They trans- form themselves into egg- shaped zoosperms by the formation of a capsule and the production of several spores from their granular contents. In Coccidium oviformc from the liver of man and of the rabbit there arc only four spores formed, which become sickle- shaped iG. ATA.—Covchhim oviforme from the liver of the rabbit, 550 diam. (after R. Leuckart). c, d. Stages of si)oro formation wliich have only been observed outside the cells. CHAPTER VII. CCELENTERATA (Zoophytes).* Radially symmetrical animals vnth a body composed of cells. They have a body-cavity lohich serves alike for circulation and diyestioii (gastrovascular S2)ace). Amongst the Cuelenterata we meet for the first time with organs and tissues composed of cells. In addition to the external and internal epithelium, cuticular, calcareous, and silicious structures, as well as muscles, nerves, and sense-organs are very generally present. On the other hand, the internal svu-face of the body is not difter- entiated into organs of circulation and digestion distinct fi-om each other. The vegetative processes are performed by the internal sur- face of the gastric cavity, the gastrovascular space, of which the central part functions as stomach and intestine, the peripheral as vascular system. R. Leuckart was the first to recognise the importance of these characters, and made use of them to separate the Polyps and the Medusce from the Echinoderms, thus resolving Cuvier's t
Size: 2334px × 1071px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectanimals, bookyear1892
