§4.13.1#113 Τα μὲν οὖν τῶν ὀρνίθων μόρια τὸν τρόπον ἔχει τοῦτον.
13 Now, the parts of birds are in this manner.
τὸ δὲ τῶν ἐχθύων γένος ἔτι μᾶλλον κεκολόβωται τῶν ἐκτὸς μορίων.
But the class of fish is still more mutilated in regard to their external parts.
οὔτε γὰρ σκέλη οὔτε χεῖρας οὔτε πτέρυγας ἔχουσιν (εἴρηται δὲ περὶ τούτων ἡ αἰτία πρότερον), ἀλλ᾿ ὅλον ἀπὸ τῆς κεφαλῆς τὸ κύτος συνεχές ἐστι μέχρι τῆς οὐρᾶς.
For they have neither legs, nor hands, nor wings (the cause for these has been stated before), but the whole trunk is continuous from the head to the tail.
ταύτην δʼ οὐχ ὁμοίαν ἔχουσι πάντες, ἀλλὰ τὰ μὲν παραπλησίαν, τῶν δὲ πλατέων ἔνια ἀκανθώδη καὶ μακράν· ἡ ἐκεῖθεν γὰρ αὔξησις γίνεται εἰς τὸ πλάτος, οἷόν ἐστι νάρκαις καὶ τρυγόσι καὶ εἴ τι τοιοῦτον ἄλλο σέλαχός ἐστιν.
And they do not all have this tail alike, but some have it similar [to other animals], while some of the flat ones have it thorny and long; for the growth from that part is directed towards width, as is the case in torpedoes, sting-rays, and if there is any other such cartilaginous fish.
τῶν μὲν οὖν τοιούτων ἀκανθῶδες καὶ μακρὸν τὸ οὐραῖόν ἐστιν, ἐνίων δὲ σαρκῶδες μὲν βραχὺ δὲ διὰ τὴν αὐτὴν αἰτίαν διʼ ἥνπερ ταῖς νάρκαις· διαφέρει γὰρ οὐδέν, ἢ βραχὺ μὲν σαρκωδέστερον δέ, ἢ μακρὸν μὲν ἀσαρκότερον δʼ εἶναι.
Therefore, in such animals, the tail is thorny and long, but in some it is fleshy and short for the same reason as in torpedoes; for it makes no difference whether it is short and more fleshy, or long and less fleshy.
ἐπὶ δὲ τῶν βατράχων τὸ ἐναντίον συμβέβηκεν· διὰ γὰρ τὸ μὴ σαρκῶδες εἶναι τὸ πλάτος αὐτῶν τὸ ἐμπρόσθιον, ὅσον ἀφῄρηται σαρκῶδες, πρὸς τὸ ὄπισθεν αὐτὸ ἔθηκεν ἡ φύσις καὶ τὴν οὐράν.
But in the case of frog-fish, the opposite has occurred; for because their front width is not fleshy, as much of the fleshy part as has been removed, nature has placed at the back and on the tail.
οὐκ ἔχουσι δʼ ἀπηρτημένα κῶλα οἱ ἰχθύες διὰ τὸ νευστικὴν εἶναι τὴν φύσιν αὐτῶν κατὰ τὸν τῆς οὐσίας λόγον, ἐπεὶ οὔτε περίεργον οὐδὲν οὔτε μάτην ἡ φύσις ποιεῖ.
And fish do not have separate limbs because their nature is adapted for swimming according to the definition of their essence, since nature does nothing superfluous or in vain.
ἐπεὶ δʼ ἔναιμά ἐστι κατὰ τὴν οὐσίαν, διὰ μὲν τὸ νευστικὰ εἶναι πτερύγια ἔχει, διὰ δὲ τὸ μὴ πεζεύειν οὐκ ἔχει πόδας· ἡ γὰρ τῶν ποδῶν πρόσθεσις πρὸς τὴν ἐπὶ τῷ πεδίῳ κίνησιν χρὴσιμός ἐστιν.
And since they are red-blooded in their essence, on the one hand, because they are adapted for swimming they have fins, and on the other hand, because they do not walk on land they do not have feet; for the addition of feet is useful for movement on flat ground.
ἅμα δὲ πτερύγια τέτταρα καὶ πόδας οὐχ οἷόν τʼ ἔχειν, οὐδʼ ἄλλο κῶλον τοιοῦτον οὐδέν· ἔναιμα γάρ.
And at the same time, it is impossible to have four fins and feet, nor any other such limb; for they are red-blooded.
οἱ δὲ κορδύλοι βράγχια ἔχοντες πόδας ἔχουσιν· πτερύγια γὰρ οὐκ ἔχουσιν, ἀλλὰ τὴν οὐρὰν μανώδη καὶ πλατεῖαν.
But the kordylos, while having gills, has feet; for they do not have fins, but a tail that is loose and flat.
ἔχουσι δὲ τῶν ἰχθύων ὅσοι μὴ πλατεῖς, καθάπερ βάτος καὶ τρυγών, τέτταρα πτερύγια, δύο μὲν ἐν τοῖς πρανέσι, δύο δʼ ἐν τοῖς ὑπτίοις.
And all fish that are not flat, unlike the ray and the sting-ray, have four fins, two on the upper side, and two on the lower side.
πλείω δὲ τούτων οὐδείς· ἄναιμοι γὰρ ἂν ἦσαν.
And none has more than these; for they would then be bloodless.
τούτων δὲ τὰ μὲν ἐν τῷ πρανεῖ σχεδὸν πάντες ἔχουσι, τὰ δʼ ἐν τοῖς ὑπτίοις ἔνιοι τῶν μακρῶν καὶ πάχος ἐχόντων οὐκ ἔχουσιν, οἷον ἐγχέλυς καὶ γόγγρος καὶ κεστρέων τι γένος τὸ ἐν τῇ λίμνῃ τῇ ἐν Σιφαῖς.
And of these, almost all have those on the upper side, but some of the long and thick ones do not have those on the lower side, such as the eel, the conger, and a certain kind of mullet in the lake at Siphae.
ὅσα δʼ ἐστὶ μακροφυέστερα καὶ ὀφιώδη μᾶλλον, οἷον σμύραινα, οὐδὲν ἔχουσι πτερύγιον ἀπλῶς, ἀλλὰ ταῖς καμπαῖς κινοῦνται, χρώμεναι τῷ ὑγρῷ ὡσπερ οἱ ὄφεις τῇ γῇ· τοῦτον γὰρ τὸν τρόπον οἱ ὄφεις νέουσιν ὅνπερ ἐπὶ τῆς γῆς ἕρπουσιν.
And those that are more elongated and rather snake-like, such as the moray eel, have no fin at all, but move by their bends, using the liquid just as snakes use the land; for in this very manner snakes swim in the same way as they creep on the land.
αἰτία δὲ τού μὴ ἔχειν τοὺς ὀφιώδεις τῶν ἐχθύων πτερύγια, ἥπερ καὶ τῶν ὄφεων τοῦ ἄποδας εἶναι.
And the cause of the snake-like fish not having fins is the same as that of snakes being footless.
τὸ δʼ αἴτιον ἐν τοῖς περὶ πορείας καὶ κινήσεως τῶν ζῴων εἴρηται.
And the cause has been stated in the treatise on the gait and movement of animals.
ἢ γὰρ κακῶς ἂν ἐκινοῦντο, τέτταρσι σημείοις κινούμενα.
For they would move poorly, moving by four points.
εἴτε γὰρ σύνεγγυς εἶχον τὰ πτερύγια, μόγις ἂν ἐκινοῦντο, εἴτε πόρρω, διὰ τὸ πολὺ μεταξύ.
For if they had their fins close together, they would move with difficulty, and if far apart, because of the great distance between.
εἰ δὲ πλείω τὰ κινητικὰ σημεῖα εἶχον, ἄναιμα ἂν ἦν.
And if they had more moving points, they would be bloodless.
ἡ δʼ αὐτὴ αἰτία καὶ ἐπὶ τῶν δύο μόνον ἐχόντων πτερύγια ἰχθύων· ὀφιώδη γάρ ἐστι καὶ εὐμηκέστερα, καὶ χρῆται τῇ κάμψει ἀντὶ τῶν δύο πτερυγίων.
And the same cause applies also to fish that have only two fins; for they are snake-like and rather long, and use their bending instead of the two fins.
διὸ καὶ ἐν τῷ ξηρῷ ἕρπουσι καὶ ζῶσι πολύν χρόνον, καὶ τὰ μὲν οὐκ εὐθύ, τὰ δʼ οἰκεῖα τῆς πεξῆς ὄντα φύσεως ἧττον ἀσπαρίζει.
Wherefore they also creep on dry land and live for a long time, and some do not wriggle immediately, while those that are akin to the terrestrial nature wriggle less.
αὐτῶν δὲ τῶν πτερυγίων τὰ ἐν τοῖς πρανέσιν ἔχει τὰ δύο ἔχοντα πτερύγια μόνον, ὅσα μὴ κωλύεται διὰ τὸ πλάτος.
And of the fins themselves, those that have only two fins have those on the upper side, unless they are prevented by their width.
τὰ δʼ ἔχοντα πρὸς τῇ κεφαλῇ ἔχει διὰ τὸ μὴ ἔχειν μῆκος ἐν τῷ τόπῳ, ᾧ ἀντὶ τούτων κινήσεται· ἐπὶ γὰρ τὴν οὐρὰν πρόμηκες τὸ τῶν τοιούτων ἐστὶν ἐχθύων σῶμα.
And those that do have them have them near the head because they do not have length in the place by which they will move instead of them; for the body of such fish is elongated towards the tail.