CHAP. 73. (49.)—THE MALADIES OF FISHES.
We do not find it stated that all kinds of fishes are subject to epizoötic diseases,[2765] like other animals of a wild nature: but it is evidently the fact that individuals[2766] among them are attacked by maladies, from the emaciated appearance that many present, while at the same moment others of the same species are taken quite remarkable for their fatness.
CHAP. 74. (50.)—THE GENERATION OF FISHES.
The curiosity and wonder which have been excited in mankind by this subject, will not allow me any longer to defer giving an account of the generation of these animals. Fishes couple by rubbing their bellies[2767] against one another; an operation, however, that is performed with such extraordinary celerity as to escape the sight. Dolphins[2768] also, and other animals of the cetaceous kind, couple in a similar manner, though the time occupied in so doing is somewhat longer. The female fish, at the season for coupling, follows the male, and strikes against its belly with its muzzle; while the male in its turn, when the female is about to spawn, follows it and devours[2769] the eggs. But with them, the simple act of coupling is not sufficient[2770] for the purposes of reproduction; it is necessary for the male to pass among the eggs which the female has produced, in order to sprinkle them with its vitalizing fluid. This does not, however, reach all the eggs out of so vast a multitude; indeed, if it did, the seas and lakes would soon be filled, seeing that each female produces these eggs in quantities innumerable.[2771]
(51.) The eggs[2772] of fishes grow in the sea; some of them with the greatest rapidity, those of the muræna, for instance; others, again, somewhat more slowly. Those among the flat fishes,[2773] whose tails or stings are not in the way, as well as those of the turtle kind, couple the one upon the other: the polypus by attaching one of its feelers to the nostrils[2774] of the female, the sæpia and loligo, by means of the tongue; uniting the arms, they then swim contrary ways; these last also bring forth at the mouth. The polypi,[2775] however, couple with the head downwards towards the ground, while the rest of the soft[2776] fish couple backwards in the same manner as the dog; cray-fish and shrimps do the same, and crabs employ the mouth.
Frogs leap the one upon the other, the male with its fore-feet clasping the armpits of the female, and with its hinder ones the haunches. The female produces tiny pieces of black flesh, which are known by the name of gyrini,[2777] and are only to be distinguished by the eyes and tail; very soon, however, the feet are developed, and the tail, becoming bifurcate, forms the hind legs. It is a most singular thing, but, after a life of six months’ duration, frogs melt away[2778] into slime, though no one ever sees how it is done; after which they come to life again in the water during the spring, just as they were[2779] before. This is effected by some occult operation of Nature, and happens regularly every year.
Mussels, also, and scallops are produced in the sand by the spontaneous[2780] operations of nature. Those which have a harder shell, such as the murex and the purple, are formed from a viscous fluid like saliva, just as gnats are produced from liquids turned sour,[2781] and the fish called the apua,[2782] from the foam of the sea when warm, after the fall of a shower.