. Cuvier's animal kingdom : arranged according to its organization. Animals. 438 they form a current in the water. In the males, both or one of them are constricted and knotted. The upper an- tennÅ were, previous to the researches of Jurine, considered as organs of generation, from the manner in which they are used during coupling. The females are provided, on each side of the tail, with an oval sac, or external ovary, filled with eggs, and attached by a very slender peduncle. A single act of impregnation is sufficient for several successive generations. The female is able to produ
. Cuvier's animal kingdom : arranged according to its organization. Animals. 438 they form a current in the water. In the males, both or one of them are constricted and knotted. The upper an- tennÅ were, previous to the researches of Jurine, considered as organs of generation, from the manner in which they are used during coupling. The females are provided, on each side of the tail, with an oval sac, or external ovary, filled with eggs, and attached by a very slender peduncle. A single act of impregnation is sufficient for several successive generations. The female is able to produce as many as ten broods in the course of three months. At their birth, the young have only four feet ; and the body is rounded, and destitute of a tail. These individuals were considered by Millier as forming a distinct genus, named Amymone. Some time aftei-wards (fifteen days in February and March), they acquire another pair of legs, in which state they constitute Miiller's genus Naupliits. After the first moulting, they have the same form and organs as the perfect insect, but the latter are of smaller size. After two more moultings, they are able to propagate their species. The majority of these Crustacea swim back downwards, darting about with great agility, and moving both backwards and for- wards with equal ease. In the absence of animal matter, they attack vegetable substances. Cyclops staphylinusâin its shorter antennae, which vary in the number of their joints, and in the gradual nar- rowing of the body, as well as in the cui-ved corneous point with which the under-side of the base of the tail is armedâforms a separate division in the genus. Cyclops castor, and some other species, having the antennae and mandibular palpi divided into two branches, form another division. The subgenus Calanus of Leach is described as having no inferior antennae ;âbut is this statement original ? ITie type of the genus is the Cyclops quadricornis (Monoctdus quadricornis, Linn. ; and C
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Keywords: ., bookcentury1800, bookdecade1840, bookpublishe, booksubjectanimals
