The porifera and coelentera . rallite of Euphyllia, showing the formation of the theca,Th, from the peripheral ends of the septa ; SS, dissepiments. (Original.) distal moieties oT the corallites have the characters of edge-zone,whilst the spaces between the corallites are covered with coenosarc,the latter shading imperceptibly into the former. For a fulldescription of these relations the reader is referred to FowlersMemoirs (22-26). Budding takes place in an analogous manner in perforate corals,but the relations between edge-zone and coelenteron, referred to 68 THE ANTHOZOA above, induce modif
The porifera and coelentera . rallite of Euphyllia, showing the formation of the theca,Th, from the peripheral ends of the septa ; SS, dissepiments. (Original.) distal moieties oT the corallites have the characters of edge-zone,whilst the spaces between the corallites are covered with coenosarc,the latter shading imperceptibly into the former. For a fulldescription of these relations the reader is referred to FowlersMemoirs (22-26). Budding takes place in an analogous manner in perforate corals,but the relations between edge-zone and coelenteron, referred to 68 THE ANTHOZOA above, induce modifications in the process. The canal systemwhich permeates the porous theca becomes much extended, and, asit extends, calcareous tissue is deposited between the network ofcanals, so that the theca appears to be enormously the mesenteries do not share in this extension, and so theedge-zone proper—that is to say, the soft tissue which is external tothe calyx, and is supported on prolongations of the mesenteries—. Fio. XXXII. 1.—Section through a braiichlet of Madrepora, sp. ? showing an axial zooid with septa, thesurrounding coenenchyme, and two buds, h, b. 2.—Diagram of a longitudinal section of Mailrrpora dvririllei, showing the perforationsin the stonio<laeuin leading into canals hollowed out in the mesenteries. M, mesentery; .s,septum ; Th, theca ; 7s, perisarc. 3.—Diagram of tlie various fonns and conditions of the mesenteries in a zooid of Maiirrpmadurinlki. Dw niiscnteries numbered 1,1; 2, 2 ; 8, 3, and bear no tllament and are simple ; thoremainder are moditied, and bear filaments below the level of the stonio<iaeum. 4. — niagram of a transverse section of a zooid of the same species. Ps, perisarc. f).—Tnmsverso section of a modilled mesentery of A/, dnrvillei, passing through two ami.•»of the stomodajal canal. Tlie thickened endoderm of the moditied mesentery is clearly seen. (1 original; the rest after Fowler.) becomes limited to the n
Size: 1801px × 1388px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubje, booksubjectctenophora
