§2Τριῶν δὲ μερῶν ὄντων εἰς ἃ διαιρεῖται πάντα τὰ τέλεια τῶν ζῴων, ἑνὸς μὲν ᾗ δέχεται τὴν τροφήν, ἑνὸς δ’ ᾗ τὸ περίττωμα προΐεται, τρίτου δὲ τοῦ μέσου τούτων, τοῦτο ἐν μὲν τοῖς μεγίστοις τῶν ζῴων καλεῖται στῆθος, ἐν δὲ τοῖς ἄλλοις τὸ ἀνάλογον, διήρθρωται δὲ μᾶλλον ἑτέροις ἑτέρων.
While there are three parts into which all perfect animals are divided—one by which it receives food, one by which it discharges the residue, and a third which is the middle of these—this third part, in the largest animals, is called the chest, and in the others its analogue, and it is more clearly articulated in some than in others.
Ὅσα δ’ αὐτῶν ἐστὶ πορευτικά, πρόσκειται καὶ μόρια τὰ πρὸς ταύτην τὴν ὑπηρεσίαν, οἷς τὸ πᾶν οἴσουσι κύτος, σκέλη τε καὶ πόδες καὶ τὰ τούτοις ἔχοντα τὴν αὐτὴν δύναμιν.
And as many of them as are capable of locomotion have also parts attached for this service, by which they carry the whole body, namely legs and feet and those parts having the same power as these.
Ἀλλ’ ἥ γε τῆς θρεπτικῆς ἀρχὴ ψυχῆς ἐν τῷ μέσῳ τῶν τριῶν μορίων καὶ κατὰ τὴν αἴσθησιν οὖσα φαίνεται καὶ κατὰ τὸν λόγον· πολλὰ γὰρ τῶν ζῴων ἀφαιρουμένου ἑκατέρου τῶν μορίων, τῆς τε καλουμένης κεφαλῆς καὶ τοῦ δεκτικοῦ τῆς τροφῆς, ζῇ μεθ’ οὗπερ ἂν ᾖ τὸ μέσον.
But indeed, the principle of the nutritive soul is manifest, both by sensation and by reason, as being in the middle of these three parts; for many animals, when either of the parts is removed—both the so-called head and the receiver of food—live with whichever part the middle is present.
Δῆλον δ’ ἐπὶ τῶν ἐντόμων, οἷον σφηκῶν τε καὶ μελιττῶν, τοῦτο συμβαῖνον· καὶ τῶν μὴ ἐντόμων δὲ πολλὰ διαιρούμενα δύναται ζῆν διὰ τὸ θρεπτικόν.
This is clearly seen happening in the case of insects, such as wasps and bees; and many of those that are not insects, when divided, can live because of the nutritive principle.
Τὸ δὲ τοιοῦτον μόριον ἐνεργείᾳ μὲν ἔχει ἕν, δυνάμει δὲ πλείω· τὸν αὐτὸν γὰρ συνέστηκε τοῖς φυτοῖς τρόπον·
This part has one principle in actuality, but in potentiality many; for it is constituted in the same way as plants.
καὶ γὰρ τὰ φυτὰ διαιρούμενα ζῇ χωρίς, καὶ γίνεται πολλὰ ἀπὸ μιᾶς ἀρχῆς δένδρα.
For plants also, when divided, live separately, and many trees come from a single principle.
Δι’ ἢν δ’ αἰτίαν τὰ μὲν οὐ δύναται διαιρούμενα ζῆν, τὰ δ’ ἀποφυτεύεται τῶν φυτῶν, ἕτερος ἔσται λόγος.
But as for the cause why some cannot live when divided, while some of the plants can be propagated by cuttings, that will be another discussion.
Ἀλλ’ ὁμοίως ἔχει κατά γε τοῦτο τά τε φυτὰ καὶ τὸ τῶν ἐντόμων γένος.
Nevertheless, plants and the class of insects are in a similar state in this respect at least.
Ἀνάγκη δὲ καὶ τὴν θρεπτικὴν ψυχὴν ἐνεργείᾳ μὲν ἐν τοῖς ἔχουσιν εἶναι μίαν, δυνάμει δὲ πλείους, Ὁμοίως δὲ καὶ τὴν αἰσθητικὴν ἀρχήν· φαίνεται γὰρ ἔχοντα αἴσθησιν τὰ διαιρούμενα αὐτῶν.
And it is necessary that the nutritive soul also be one in actuality in those that possess it, but many in potentiality, and likewise the sensory principle; for their divided parts appear to possess sensation.
Ἀλλὰ πρὸς τὸ σώζεσθαι τὴν φύσιν, τὰ μὲν φυτὰ δύναται, ταῦτα δ’ οὐ δύναται διὰ τὸ μὴ ἔχειν ὄργανα πρὸς σωτηρίαν, ἐνδεᾶ τ’ εἶναι τὰ μὲν τοῦ ληψομένου τὰ δὲ τοῦ δεξομένου τὴν τροφήν, τὰ δ’ ἄλλων τε καὶ τούτων ἀμφοτέρων.
However, with respect to preserving their nature, plants are able to do so, but these animals are not, because they do not possess organs for self-preservation, some being in need of that which will take food, others of that which will receive it, and others of other organs or both of these.
Ἐοίκασι γὰρ τὰ τοιαῦτα τῶν ζῴων πολλοῖς ζῴοις συμπεφυκόσιν· τὰ δ’ ἄριστα συνεστηκότα τοῦτ’ οὐ πάσχει τῶν ζῴων διὰ τὸ εἶναι τὴν φύσιν αὐτῶν ὡς ἐνδέχεται μάλιστα μίαν.
For such animals resemble many animals grown together; but those animals which are most excellently constituted do not suffer this, because their nature is, as far as possible, one.
Διὸ καὶ μικρὰν αἴσθησιν ἔνια ποιεῖ διαιρούμενα τῶν μορίων, ὅτι ἔχει τι ψυχικὸν πάθος· χωριζομένων γὰρ τῶν σπλάγχνων ποιεῖται κίνησιν, οἷον καὶ αἱ χελῶναι τῆς καρδίας ἀφῃρημένης.
That is why even some of the divided parts produce a slight sensation, because they retain some affection of the soul; for even when the viscera are separated, they produce motion, as turtles do when their heart has been removed.