philosopher whose attention has been attracted to the subject. They are in general oviparous, or egg-producing; but there are a few, such as the eel and the blenny, which are viviparous, or produce their young alive. The males have the _milt_ and the females the _roe_; but some individuals, as the sturgeon and the cod tribes, are said to contain both. The greater number deposit their spawn in the sand or gravel; but some of those which dwell in the depths of the ocean attach their eggs to sea-weeds. In every instance, however, their fruitfulness far surpasses that of any other race of animals. According to Lewenhoeck, the cod annually spawns upwards of nine millions of eggs, contained in a single roe. The flounder produces one million; the mackerel above five hundred thousand; a herring of a moderate size at least ten thousand; a carp fourteen inches in length, according to Petit, contained two hundred and sixty-two thousand two hundred and twenty-four; a perch deposited three hundred and eighty thousand six hundred and forty; and a female sturgeon seven millions six hundred and fifty-three thousand two hundred. The viviparous species are by no means so prolific; yet the blenny brings forth two or three hundred at a time, which commence sporting together round their parent the moment they have come into existence.