The animal kingdom : arranged after its organization, forming a natural history of animals, and an introduction to comparative anatomy . t during the growth into four lobes ; and theminute serratures which appear on the edges ofthese are the commencement of the lobes andfringes which are observed on the tentacula of the adult animal. The reproductive organs are atlast evolved, the sexes being kept distinct; ;ova are produced, from which the animalcular embryo is developed as before into a polypoid body. The propagation of the MeduscB is not only effected by ova, but also in some instances by g
The animal kingdom : arranged after its organization, forming a natural history of animals, and an introduction to comparative anatomy . t during the growth into four lobes ; and theminute serratures which appear on the edges ofthese are the commencement of the lobes andfringes which are observed on the tentacula of the adult animal. The reproductive organs are atlast evolved, the sexes being kept distinct; ;ova are produced, from which the animalcular embryo is developed as before into a polypoid body. The propagation of the MeduscB is not only effected by ova, but also in some instances by gemmation ; anotherindication of their close alliance to Zoophytes. This has been observed by Sars in Cytais octopnnctata [Lizzia ofProfessor E. Forbes, op. cit.), and by Professor E. Forbes in two species of Sarsia. In the former case, thegt-mmffi are produced from the externiil wall of the stomach ; in Sarsia gemmi/cra, they grow from the lower p»rtof the peduncle, or proboscis-like prolongation of the mouth ; and in Sarsia proli/cra they spring from the basesof the tentacula that hang from 1 : growth, by a difference : the rate. f Medusa—Disks I nd by their agency gation of the mouth ;in of thedisli. 698 RADIATA. CLASS POLYPI. Of this class, now more commonly termed Polypifeba, much more is now known than was knownto Cuvier; and his classification has altogether given place to one in which the primary characters aredrawn from the structure of the animal, that derived from the compound mass or polypidom being ofsecondary importance. The separation of the Carnosi or Aciiniform polypes from the Gelalinosi orSydraform polypes, was, as we shall see, quite correct; but, on the other hand, the separation ofthe solitary genera from the compound forms of the same groups was altogether erroneous. Thusamong the Coraliiferi of Cuvier, the greater part of the first family is composed of Hydraformpolypes; the second is made up of one genus (Cellularia) which is not a Zoophyte at all, bu
Size: 1961px × 1274px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorwe, bookcentury1800, bookdecade1840, booksubjectanimals
