[2801] Our periwinkles.
[2802] All the chondropterygian fishes, Cuvier says, have, in addition to their ovaries, real oviducts, which the ordinary fishes have not; the lower part of which, being detached, acts as the uterus, into which the eggs descend when they have gained their proper size: and it is here that the young ones burst forth from the egg, when the parent animal is viviparous.
[2803] Aristotle, Hist. Anim. B. vi. c. 13, says the same of the glanis, or silurus.
[2804] The Syngnathus acus of Linnæus. This fish, Cuvier says, and in general all of the same genus, has a channel situate under the tail, which is opened by two moveable valves. In this they deposit their eggs at the moment of excluding them. After this, the valves open, to give a passage to the eggs, or the young enclosed in them. This circumstance, he says, gave rise to the notion mentioned in the text.
[2805] Mentioned in c. 35 of the present Book. Cuvier says that the sea tortoises, or turtles, to which no doubt this animal belonged, do deposit their eggs much in the way here mentioned.
[2806] Both these fishes have been mentioned in c. 23 of the present Book.
[2807] Pliny means to say, Cuvier says, that all these fish are to be looked upon as females: and, in fact, he says, Cavolini discovered eggs and a milt in every one that he examined; so that they appear to have all the appliances of self-fecundation.
[2808] Or wheel-fish: from the Greek τροχὸς, “a wheel.” It is not clearly known what animal he alludes to under this name. Snails, Cuvier says, are hermaphrodites, and so is the helix, but still they require sexual connection for the purposes of reproduction. The greater part of the marine uni-valves, on the other hand, are of separate sexes; but the organ of the male being proportionally of great length, and coiled in part beneath its mantle, this fact may very possibly have given rise to the notion here mentioned by our author, that the animal impregnates itself.
[2809] This can only be understood, Cuvier says, as applying to those animals the young of which are still enveloped in the membranes of the egg; for in general, the young of fish, from the moment of their birth, have eyes of great beauty, and are remarkable for the quickness of their sight.
[2810] From the Greek παυσίλυπον, “grief-assuaging.” This was the name of a splendid villa belonging to Vedius Pollio, and which he bequeathed to Augustus. It was famous for its fish preserves; and it was here probably that Pollio kept his murenæ, previously mentioned by Pliny as being fed on human flesh. The vicinity is still called Monte Posilipo.