Those aquatic animals which are covered with hair are viviparous, such, for instance, as the pristis, the balæna,2307 and the sea-calf. This last brings forth its young on land, and, like the sheep, produces an after-birth. In coupling, they adhere after the manner of the canine species; the female sometimes produces even more than two, and rears her young at the breast. She does not take them down to the sea until the twelfth day, and after that time makes them become used to it by degrees.2308 These animals are killed with the greatest difficulty, unless the head is cut off at once. They make a noise which sounds like lowing, whence their name of “sea-calf.” They are susceptible, however, of training, and with their voice, as well as by gestures, can be taught to salute the public; when called by their name, they answer with a discordant kind of grunt.2309 No animal has a deeper sleep2310 than this; on dry land it creeps along as though on feet, by the aid of what it uses as fins when in the sea. Its skin, even when separated from the body, is said to retain a certain sensitive sympathy with the sea, and at the reflux2311 of the tide, the hair on it always rises upright: in addition to which, it is said that there is in the right fin a certain soporiferous influence, and that, if placed under the head, it induces sleep.

(14.) There are only two animals without hair that are viviparous, the dolphin and the viper.2312