It is quite clear from the above quotations that there is an analogy, if not a close one, between the reproductive organs of the blenny and those of the viviparous fish from the North-west seas; for ‘the fœtal sac of the gravid female’ evidently means that there is a kind of placental sac, in which the young are contained; but it leaves us quite as much in the dark as ever as to how fœtal life is supported. As the ova deposited in the usual way (when fecundated) contains all that is requisite for the development of the embryo, it is just possible that the same process goes on in the womb of the female viviparous fish, and that the fœtal sac is only a wrapper, formed by the widened end of the ovary. But still I maintain that it fulfils a far more important duty. I fear I have been rather prolix in the foregoing descriptions, but I must plead the novelty and importance of the subject as my excuse. The most beautiful of all the species of these fish is the sapphire perch (so called by the traders), very plentiful in Puget’s Sound. Eighteen exquisitely beautiful mazarine-blue lines or stripes mark its entire length from head to tail; and above and below this line are a number of spots of most dazzling blue, arranged in a crescent shape, about the eyes and gill-covers. Between these spots the colour changes, as it does in the dolphin, throwing off a kind of phosphorescent light of varying shades of gold, purple, and green—the back bright-blue but darker than the stripes; the belly white, marked by golden-yellow streaks. But now for the most important feature in the history of these fish—that of bringing into the world their young alive, self-dependent, and self-supporting, as perfect in their minutest organisation as the parent-fish that gives them birth. The generative apparatus of the female fish when in a gravid state may be defined as a large bag or sac. Ramifying over its surface may be seen a most complicated and strangely beautiful vascular arrangement—a network of vessels, the use of which is clearly to convey the lifegiving fluid to the infant fish, and carry it back again, after having served its destined purpose, to be revivified for future use. The way this sac is, as it were, folded, and the different compartments made for the accommodation of the embryonic fish, is most singular, and very difficult to describe clearly.