§77 Τὴν τῶν ὀστῶν φύσιν ἄρα σκεπτέον εἰ πρὸς κίνησιν ἢ πρὸς ἔρεισμα καὶ πρὸς τὸ στέγειν καὶ περιέχειν, ἔτι δʼ εἰ ὥσπερ ἀρχαὶ ἔνια, καθάπερ ὁ πόλος.
Therefore, we must consider the nature of bones, whether it is for movement, or for support, and for covering and enclosing, and further whether some of them are like principles, just as the pole [is].
λέγω δὲ πρὸς μὲν κίνησιν, οἷον ποδὸς ἢ χειρὸς ἢ σκέλους ἢ ἀγκῶνος, ὁμοίως τήν τε καμπτικὴν καὶ τὴν κατὰ τόπον· οὐδὲ γὰρ τὴν τοπικὴν οἷόν τε ἄνευ κάμψεως.
I mean for movement, such as of a foot or a hand or a leg or an elbow, likewise both that of bending and that of place; for indeed locomotion is not possible without bending.
σχεδὸν δὲ καὶ τὰ ἐρείσματα ἐν τούτοις.
And almost all supports are among these.
τὴν δὲ τοῦ στέγειν καὶ περιέχειν, οἷον τὰ ἐν τῇ κεφαλῆ τὸν ἐγκέφαλον, καὶ ὅσοι δὴ τὸν μυελὸν ἀρχήν.
And [I mean] that of covering and enclosing, such as the [bones] in the head [covering] the brain, and as many [theories] indeed as make the spinal cord the principle.
αἱ δὲ πλευραὶ τοῦ συγκλείειν.
And the ribs are for the sake of enclosing.
ἀρχὴ δὲ καὶ μένον ἡ ῥάχις, ἀφʼ ἧς καὶ αἱ πλευραὶ πρὸς τὴν σύγκλεισιν.
And the spine is a principle and remains stationary, from which the ribs also [extend] for enclosing.
ἀνάγκη γὰρ εἶναί τι τοιοῦτον· ἅπαν γὰρ τὸ κινούμενον ἐξ ἠρεμοῦντος.
For it is necessary that there be something of this sort; for everything that moves [moves] from what is at rest.
ἅμα δὲ καὶ δεῖ γε εἶναι τὸ οὗ ἕνεκα.
And at the same time there must also be that for the sake of which [it moves].
ἐν ᾧ δὴ καὶ τὴν ἀρχὴν ἔνιοι, τόν τε ῥαχίτην καὶ τὸν ἐγκέφαλον.
In which indeed some also place the principle, namely the spine and the brain.
ἔτι δὲ παρὰ ταῦτʼ ἐπισυναφῆς καὶ συγκλείσεως χάριν, οἷον ἡ κλείς· ὅθεν ἴσως καὶ τοὔνομα.
And further, besides these, [some bones are] for the sake of additional connection and enclosing, such as the collarbone; whence perhaps also its name.
πρὸς δὲ τὴν χρείαν ἕκαστον καλῶς.
And each is well [made] for its utility.
οὐδὲ γὰρ ἡ κάμψις, οὔτε τοῦ ὅλου οὔτε τῶν μερῶν, εἰ μὴ τοιαῦτα, οἷον ῥάχις, πούς, ἀγκών.
For there would be no bending, either of the whole or of the parts, unless they were of such a kind, like the spine, the foot, the elbow.
εἴσω γὰρ δεῖ τὴν κάμψιν πρὸς τὴν χρείαν, ὁμοίως δὲ καὶ τὴν τοῦ ποδὸς καὶ τῶν ἄλλων τοιαύτην.
For the bending must be inward for its utility, and likewise that of the foot and of the others is of this kind.
ἅπαντα δὲ ἕνεκά του, καὶ τὰ ἐν τούτοις ὀστᾶ, οἷον ἡ ἐν τῷ ἀγκῶνι κερκὶς ἕνεκα τῆς στροφῆς τοῦ ἀγκῶνος καὶ τῆς χειρός.
And everything is for the sake of something, and the bones in these [parts] as well, such as the radius in the elbow for the sake of the rotation of the elbow and the hand.
οὐ γὰρ ἂν ἐδυνάμεθα πρηνῆ καὶ ὑπτίαν κινεῖν ἄνευ ταύτης, οὐδὲ τοὺς πόδας ἐπαίρειν καὶ κάμπτειν, εἰ μὴ δύο αἱ ἐν τῇ κινήσει κερκίδες.
For we would not be able to move them prone and supine without this, nor to raise and bend the feet, if there were not two "radii" in the movement.
ὡσαύτως δὲ καὶ τὰ ἄλλα σκεπτέον, οἷον ἡ τοῦ τραχήλου κίνησις, εἰ ἓν τὸ ὀστοῦν.
And likewise the other things must be considered, such as the movement of the neck, if the bone is one.
δεῖ δὲ καὶ ὅσα πρὸς κατάληψιν ἢ σύνδεσμον, οἷον ἡ μύλη ἡ ἐπὶ τῷ γόνατι.
And we must also [consider] those for grasping or binding, such as the patella on the knee.
ἀλλὰ καὶ διὰ τί τοῖς ἄλλοις οὔ.
But also why [this is] not in the others.
ὅσα μὲν οὖν κινητικά, πάντα μὲν μετὰ νεύρων, ἴσως δʼ ὅσα πρακτικῶς, μάλιστα, οἷον τὰ περὶ ἀγκῶνα καὶ σκέλη καὶ χεῖρας καὶ πόδας.
Those then that are motive are all with tendons, and perhaps most of all those that are practical, such as those about the elbow, legs, hands, and feet.
τὰ δʼ ἄλλα συνδέσμου χάριν, ὅσα δεῖται.
But the others are for the sake of binding, as many as need it.
ἐνίοις γὰρ ἴσως οὐδὲν ἢ ἐπʼ ὀλίγον, οἷον ἡ ῥάχις· ἀλλʼ ἡ κάμψις. || καὶ γὰρ ἡ πρὸς ἄλληλα κόλλησις ἰχώρ ἐστι καὶ ὑγρότης μυξώδης. || τὰ δὲ καὶ συνδεῖται νεύροις, οἷον τὰ περὶ τὰ ἄρθρα.
For in some perhaps there is none or only a little, as in the spine; but [there is] bending, || for indeed the glueing together of one to another is ichor and a slimy moisture. || But some are also bound together by tendons, such as those about the joints.
§8Πάντων δʼ ἐστὶ λόγος ὁ βελτίων ὡς καὶ νῦν ζητεῖν· 8 ἀλλὰ τὰς ἀρχὰς ἐφʼ ἱκανόν, ὧν χάριν, σκεπτέον.
And of all things there is a better explanation, as we are seeking even now; 8 but we must sufficiently consider the principles, for the sake of which [they exist].
οὐκ ἂν δόξειε κινήσεως ἕνεκα τὰ ὀστᾶ, ἀλλὰ μᾶλλον τὰ νεῦρα ἢ τὰ ἀνάλογον, ἐν ᾡ πρώτῳ τὸ πνεῦμα τὸ κινητικόν, ἐπεὶ καὶ ἡ κοιλία κινεῖται καὶ ἡ καρδία νεῦρα ἔχει· τὰ δʼ οὐ πᾶσιν, ἀλλʼ ἐνίοις, ἀνάγκη καὶ πρὸς τὴν τοιαύτην κίνησιν νεῦρα ἔχειν, ἢ εἰς τὲ ὁ γὰρ πολύπους ἐπʼ ὀλίγον καὶ κακῶς βαδίζει.
The bones would not seem to be for the sake of movement, but rather the tendons or their analogue, in which first is the motive breath (pneuma), since the belly also moves and the heart has tendons; but these do not belong to all, but to some, and it is necessary for such movement to have tendons, or... for the octopus walks only a little and poorly.
δεῖ γὰρ τοῦτο λαβεῖν ὥσπερ ἀρχήν, ὅτι πᾶσιν ἄλλου τινὸς χάριν ἄλλα πρὸς τὴν κίνησιν τὴν οἰκείαν, οἷον τοῖς μὲν πεζοῖς πόδας, καὶ τοῦτο τοῖς μὲν ὀρθοῖς δύο, τοῖς δὲ παντελῶς ἐπὶ τῆς γῆς πλείους, ὅσοις ἡ ὕλη γεωδεστέρα καὶ ψυχροτέρα (τὰ δὲ καὶ ἄποδα ὅλως ἐγχωρεῖ· βίᾳ γὰρ οὕτω κινεῖσθαι) τοῖς δὲ πτηνοῖς πτέρυγας, καὶ τούτων τὴν μορφὴν οἰκείαν τῇ φύσει, διάφορα δὲ τοῖς πτητικωτέροις καὶ βραδυτέροις.
For we must take this as a principle, that for all [animals] different things [are provided] for the sake of something else, for their proper movement, as for instance feet for walking animals, and of these, two for those that are upright, but more for those that are entirely on the ground, for as many as have a more earthy and colder matter (and some indeed are entirely footless, as is possible; for they move in this way by force), and wings for flying animals, and the form of these is proper to their nature, and different for those that are more capable of flight and those that are slower.
πόδας δὲ τροφῆς χάριν καὶ ἀναστάσεως, πλὴν τῆς νυκτερίδος· διὸ καὶ τὴν τροφὴν ἐκ τοῦ ἀέρος.
And feet are for the sake of food and standing up, except in the case of the bat; which is why it [takes] its food from the air.
καὶ μὴ δεῖσθαι διαναπαύσεως· οὐ δέονται γὰρ διʼ ἄλλων.
And it does not need to rest; for they do not need [rest] through other things.
τὰ δὲ ὀστρακόδερμα τῶν ἐνύδρων ὑπόποδα διὰ τὸ βάρος.
And testaceans among aquatic animals have small feet because of their weight.
καὶ ταῦτα μὲν πρὸς τὴν κατὰ τόπον ἀλλαγήν· ὅσα δὲ πρὸς τὴν ἄλλην χρείαν, ὥσπερ ὑφηγεῖται καὶ ἑκάστου τὰ ἴδια, καὶ εἴ τι μὴ προφανές, οἷον διὰ τί τὰ πολύποδα βραδύτατα. (καίτοι τὰ τετράποδα θάττω τῶν διπόδων) πότερον ὅτι ἐπὶ γῆς ὅλα τὰ σώματα ἢ ὅτι φύσει ψυχρὰ καὶ δυσκίνητα ἢ διʼ ἄλλην αἰτίαν.
And these indeed are for change of place; but as many as are for another utility, just as [nature] guides and the characteristics of each [guide], and if something is not obvious, such as why the many-footed animals are the slowest. (And yet four-legged animals are faster than two-legged ones) whether because their whole bodies are on the ground, or because they are by nature cold and hard to move, or due to some other cause.