§1## ΠΕΡΙ ΑΝΑΠΝΟΗΣ.
Περὶ γὰρ ἀναπνοῆς ὀλίγοι μέν τινες τῶν πρότερον φυσικῶν εἰρήκασιν· τίνος μέντοι χάριν ὑπάρχει τοῖς ζῴοις, οἱ μὲν οὐδὲν ἀπεφήναντο, οἱ δὲ εἰρήκασι μέν, οὐ καλῶς δ’ εἰρήκασιν ἀλλ’ ἀπειροτέρως τῶν συμβαινόντων.
## ON RESPIRATION For concerning respiration, only a few of the earlier natural philosophers have spoken; however, as to for what purpose it belongs to animals, some have declared nothing, while others have indeed spoken, but have not spoken well, but rather with too little experience of the facts.
Ἔτι δὲ πάντα τὰ ζῷά φασιν ἀναπνεῖν· τοῦτο δ’ οὐκ ἔστιν ἀληθές.
Furthermore, they assert that all animals respire; but this is not true.
Ὥστ’ ἀναγκαῖον περὶ τούτων πρῶτον ἐπελθεῖν, ὅπως μὴ δοκῶμεν ἀπόντων κενὴν κατηγορεῖν.
Consequently, it is necessary first to go over these matters, so that we may not seem to bring a groundless accusation against absent opponents.
Ὅτι μὲν οὖν ὅσα πλεύμονα ἔχει τῶν ζῴων, ἀναπνεῖ πάντα, φανερόν.
Now, that all animals which possess lungs respire is clear.
Ἀλλὰ καὶ τούτων αὐτῶν ὅσα μὲν ἄναιμον ἔχει τὸν πλεύμονα καὶ σομφόν, ἧττον δέονται τῆς ἀναπνοῆς· διὸ πολὺν χρόνον ἐν τοῖς ὕδασι δύνανται διαμένειν παρὰ τὴν τοῦ σώματος ἰσχύν.
But even among these very ones, those which have a lung that is bloodless and spongy stand in less need of respiration; wherefore they are able to remain in water for a long time, in accordance with the strength of their body.
Τὸν δὲ πλεύμονα σομφὸν ἔχει πάντα τὰ ᾠοτοκοῦντα, οἷον τὸ τῶν βατράχων γένος.
Moreover, all oviparous animals, such as the genus of frogs, have a spongy lung.
Ἔτι δὲ αἱ ἑμύδες τε καὶ χελῶναι πολὺν χρόνον μένουσιν ἐν τοῖς ὑγροῖς· ὁ γὰρ πλεύμων ὀλίγην ἔχει θερμότητα· ὀλίγαιμον γὰρ ἔχουσιν αὐτόν· ἐμφυσώμενος οὖν αὐτὸς τῇ κινήσει καταψύχει καὶ ποιεῖ διαμένειν πολὺν χρόνον.
Further, marsh turtles and sea turtles remain for a long time in liquids; for their lung has little heat, since they have it containing little blood; therefore, when it is inflated, it cools itself by its movement and enables them to remain for a long time.
Ἐὰν μέντοι βιάζηταί τις λίαν κατέχων πολὺν χρόνον, ἀποπνίγονται πάντα· οὐδὲν γὰρ τῶν τοιούτων δέχεται τὸ ὕδωρ ὥσπερ οἱ ἰχθῦς.
If, however, one forces them by holding them down for too long a time, they are all suffocated; for none of such animals receives water as fishes do.
Τὰ δ’ ἔναιμον ἔχοντα τὸν πλεύμονα πάντα μᾶλλον δεῖται τῆς ἀναπνοῆς διὰ τὸ πλῆθος τῆς θερμότητος· τῶν δ’ ἄλλων ὅσα μὴ ἔχει πλεύμονα, οὐδὲν ἀναπνεῖ.
But those which have a lung full of blood all stand in greater need of respiration because of the abundance of heat; while of the other animals, as many as do not possess a lung, none respires.
§2Δημόκριτος μὲν οὖν ὁ Ἀβδηρίτης καί τινες ἄλλοι τῶν περὶ ἀναπνοῆς εἰρηκότων οὐδὲν περὶ τῶν ἄλλων διωρίκασι ζῴων, ἐοίκασι μέντοι λέγειν ὡς πάντων ἀναπνεόντων· Ἀναξαγόρας δὲ καὶ Διογένης, πάντα φάσκοντες ἀναπνεῖν, περὶ τῶν ἰχθύων καὶ τῶν ὀστρείων λέγουσι τίνα τρόπον ἀναπνέουσιν.
Now Democritus of Abdera and certain others of those who have spoken concerning respiration have defined nothing concerning the other animals, yet they seem to speak as if all respired; whereas Anaxagoras and Diogenes, asserting that all animals respire, explain in what manner fishes and shellfish respire.
Καί φησιν Ἀναξαγόρας μέν, ὅταν ἀφῶσι τὸ ὕδωρ διὰ τῶν βραγχίων, τὸν ἐν τῷ στόματι γινόμενον ἀέρα ἕλκοντας ἀναπνεῖν τοὺς ἰχθῦς· οὐ γὰρ εἶναι κενὸν οὐδέν·
And Anaxagoras says that when they discharge the water through their gills, the fishes respire by drawing in the air that is produced in the mouth; for he says that there is no vacuum.
Διογένης δ’ ὅταν ἀφῶσι τὸ ὕδωρ διὰ τῶν βραγχίων, ἐκ τοῦ περὶ τὸ στόμα περιεστῶτος ὕδατος ἕλκειν τῷ κενῷ τῷ ἐν τῷ στόματι τὸν ἀέρα, ὡς ἐνόντος ἐν τῷ ὕδατι ἀέρος.
Diogenes, on the other hand, says that when they discharge the water through their gills, they draw the air from the water surrounding the mouth by means of the vacuum in the mouth, on the ground that there is air present in the water.
Ταῦτα δ’ ἐστὶν ἀδύνατα.
But these things are impossible.
Πρῶτον μὲν γὰρ τὸ ἥμισυ τοῦ πράγματος ἀφαιροῦσι, διὰ τὸ τὸ κοινὸν ἐπὶ θατέρου λέγεσθαι μόνον.
For in the first place, they take away half of the matter, because the common term is applied to only one of the two.
Ἀναπνοὴ γὰρ καλεῖται, ταύτης δὲ τὸ μὲν ἐκπνοή ἐστι τὸ δ’ εἰσπνοή· περὶ ἧς οὐθὲν λέγουσι, τίνα τρόπον ἐκπνέουσι τὰ τοιαῦτα τῶν ζῴων.
For it is called respiration, and of this one part is expiration and the other is inspiration; concerning which they say nothing as to in what manner such animals expire.
Οὐδ’ ἐνδέχεται αὐτοῖς εἰπεῖν· ὅταν γὰρ ἀναπνεύσωσι, ταύτῃ ᾗ ἀνέπνευσαν πάλιν δεῖ ἐκπνεῖν, καὶ τοῦτο ποιεῖν ἀεὶ παραλλάξ, ὥστε συμβαίνει ἅμα δέχεσθαι τὸ ὕδωρ κατὰ τὸ στόμα καὶ ἐκπνεῖν.
Nor is it possible for them to say; for when they have inspired, they must expire again by the same way they inspired, and do this always alternately, so that it happens that they receive water through the mouth and expire at the same time.
Ἀνάγκη δ’ ἀπαντῶντα ἐμποδίζειν θάτερον θατέρῳ.
But it is necessary that, meeting each other, the one hinders the other.
Εἶτα ὅταν ἀφῶσι τὸ ὕδωρ, τότε ἐκπνέουσι κατὰ τὸ στόμα ἢ κατὰ τὰ βράγχια, ὥστε συμβαίνει ἅμα ἐκπνεῖν καὶ ἀναπνεῖν· τότε γάρ φασιν αὐτὸ ἀναπνεῖν.
Furthermore, when they discharge the water, they then expire through the mouth or through the gills, so that it happens that they expire and inspire at the same time; for they say that it respires at that moment.
Ἄμα δ’ ἀναπνεῖν καὶ ἐκπνεῖν ἀδύνατον.
But to inspire and expire at the same time is impossible.
Ὤστ’ εἰ ἀνάγκη τὰ ἀναπνέοντα ἐκπνεῖν καὶ εἰσπνεῖν, ἐκπνεῖν δὲ μὴ ἐνδέχεται μηδὲν αὐτῶν, φανερὸν ὡς οὐδ’ ἀναπνεῖ αὐτῶν οὐδέν.
Consequently, if it is necessary for those that respire to expire and inspire, and it is not possible for any of them to expire, it is clear that none of them respires either.