Chap. 79.] 
ARTIFICIAL OTSTEE-BEDS. 
467 
have a womb ; and those which by the Greeks are called 
trochi/* it is said, impregnate themselves. The young of all 
aquatic animals are without sight at their birth. 
CHAP. 78. (53.) — THE LONGEST LIVES KNOWN AMONGST EISHES. 
We have lately heard of a remarkable instance of length of 
life in fish. Pausilypum^^ is the name of a villa in Campania, 
not far from i^"eapolis ; here, as we learn from the works of 
M. Annseus Seneca, a fish is known to have died sixty years 
after it had been placed in the preserves of Csesar^"^ by Yedius 
Pollio ; while others of the same kind, and its equals in age, 
were living at the time that he wrote. This mention of fish- 
preserves reminds me that I ought to mention a few more par- 
ticulars connected with this subject, before we leave the aquatic 
animals. 
CHAP. 79. (54.) THE FIRST PERSON THAT FORMED ARTIFICIAL 
OYSTER-BEDS. 
The first person who formed artificial oj^ster-beds was Ser- 
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 appli- 
ances of self-fecundation. 
Or wheel-fish : from the Greek TpoxoQy " 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. 
15 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. 
16 From the Greek iravaiXvirov, grief-assuaging.'' This was the 
name of a splendid villa belonging to Vedius Pollio, and which he be- 
queathed to Augustus. It was famous for its fish preserves ; and it was 
here probably that Pollio kept his murense, previously mentioned by Pliny 
as being fed on human flesh. The vicinity is still called Monte Posilipo. 
17 "Caesaris piscinis." This may either mean, preserves which had 
their name from Csesar, or preserves which afterwards belonged to Caesar. 
The work of Seneca, in which this circumstance was mentioned, is no 
longer in existence. 
H H 2 
