. The animal kingdom : arranged after its organization; forming a natural history of animals, and an introduction to comparative anatomy. Zoology. Fio. 8.—Pbodijction of Mediisa—Bitds from PoLYFB BoDlFS; a, ft, c, rf, successive stages. of the margin increase very little in size, whilst the intervals between them gradually fill up ; tubular prolongations of the stomach extend themselves over the disk, and its border becomes furnished with long pendent prehensile tentacles. The mouth, which even in the youngest detached animal allows of being greatly extended and protruded, is quad- rangular, a
. The animal kingdom : arranged after its organization; forming a natural history of animals, and an introduction to comparative anatomy. Zoology. Fio. 8.—Pbodijction of Mediisa—Bitds from PoLYFB BoDlFS; a, ft, c, rf, successive stages. of the margin increase very little in size, whilst the intervals between them gradually fill up ; tubular prolongations of the stomach extend themselves over the disk, and its border becomes furnished with long pendent prehensile tentacles. The mouth, which even in the youngest detached animal allows of being greatly extended and protruded, is quad- rangular, and presents four extensible angles. These angles grow more rapidly than the four- sided oral tube or proboscis ; so that, in the more advanced animals, the mouth appears as if it had split during the growth into four lobes ; and the minute serratures which appear on the edges of these are the commencement of the lobes and fringes which are observed on the tentacula of the f'°-9-D"-«'-"'"T0F MEDvsA-DisKSi«,,d,,,/,3acce5,iTe,ti«e, adult animal. The reproductive organs are at last evolved, the sexes being kept distinct; and by their agency ova are produced, from which the animalcular embryo is developed as before into a polypoid body. The propagation of the Medusce is not only effected by ova, but also in some instances by gemmation ; another indication of their close alliance to Zoophytes. This has been observed by Sars in Cytais oetopunetata (Lizzia of Professor E. Forbes, op. cit.), and by Professor E. Forbes in two species of Sarsia. In the former case, the gemmae are produced from the external wall of the stomach ; in Sarsia gemmifcra, they grow from the lower part of the peduncle, or proboscis-like prolongation of the mouth ; and in Sarda prolifera they spring from the bases of the tentacula that hang from the margin of the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readabili
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Keywords: ., bookauthorwe, bookcentury1800, bookdecade1860, booksubjectzoology
