Page 9

Like almost every other little point on which we happen to touch, we might make this one the starting-point (here comes in the delight and fascination of the interpreter's task!) for other stories.

Speusippus, Plato's successor in the Academy, was both philosopher and naturalist, and we may take it, if we please, that his leaning towards biology, and the biological trend which at this time became more and more marked in Athenian philosophy, were not unconnected with the great impulse which Aristotle had given. However this may be, Speusippus wrote a book περι Ὁμοιων {peri Homoiôn} 'Concerning Resemblances'; and this, of which we only possess a few fragmentary sentences, must have been a very curious and an interesting book. He mentions, among other similar cases, that our little fish phycis has a close outward semblance to the sea-perch; and this is enough to clinch the proof that Aristotle's nest-building fish was not a goby but a wrasse. The whole purport of Speusippus's book seems to have been to discuss how, or why, with all Nature's apparently infinite variety, certain animals have a singularly close resemblance to certain others, though they be quite distinct in kind. It is a problem which perplexes us still, when we are astonished and even deluded by the likeness between a wasp and a hover-fly, a merlin and a cuckoo. In certain extreme cases we call it 'mimicry', and invoke hypotheses to account for this 'mimetic' resemblance; and those of us who reject these hypotheses must fain take refuge in others, as far-reaching in their way. This at least we know, that Speusippus seized upon a real problem of biology, of lasting interest and even of fundamental importance.

To come back to Aristotle and his fishes, let us glance at one little point more. The reproduction of the eel is an ancient puzzle, which has found its full solution only in our own day. While the salmon, for instance, comes up the river to breed and goes down again to the sea, the eel goes down to the ocean to spawn, and the old eels come back no more but perish in the great waters. The eel's egg develops into a little flattened, transparent fish, altogether different in outward appearance from an eel, which turns afterwards into a young eel or 'elver'; and Professor Grassi, who had a big share in elucidating the whole matter, tells us the curious fact that he found the Sicilian fishermen well acquainted with the little transparent larva (the Leptocephalus of modern naturalists), that they knew well what it was, and that they had a name for it--_Casentula_. Now Aristotle, in a passage which I think has been much misunderstood (and which we must admit to be in part erroneous), tells us that the eel develops from what he calls γης εντερα {gês entera}, a word which we translate, literally, the 'guts of the earth', and which commentators interpret as 'earthworms'! But in Sicilian Doric, γης εντερα {gês entera} would at once become γας εντερα {gas entera}; and between 'Gasentera' and the modern Sicilian 'Casentula' there is scarce a hairbreadth's difference. So we may be permitted to suppose that here again Aristotle was singularly and accurately informed; and that he knew by sight and name the little larva of the eel, whose discovery and identification is one of the modest triumphs of recent investigation.

Previous Page / First / Next