§1.5Ἔτι δὲ τὸ ὄργανον τὸ πρὸς τὸν συνδυασμὸν τὰ μὲν τέτράποδα ἔχει· ἐνδέχεται γὰρ αὐτοῖς ἔχειν· τοῖς δ’ ὄρνισι καὶ τοῖς ἄποσιν οὐκ ἐνδέχεται διὰ τὸ τῶν μὲν τὰ σκέλη ὑπὸ μέσην εἶναι τὴν γαστέρα, τὰ δ’ ὅλως ἀσκελῆ εἶναι, τὴν δὲ τοῦ αἰδοίου φύσιν ἠρτῆσθαι ἐντεῦθεν καὶ τῇ θέσει κεῖσθαι ἐνταῦθα.
Furthermore, quadrupeds have the organ for copulation; for it is possible for them to have it; but for birds and footless animals it is not possible, because the legs of the former are under the middle of the belly, while the latter are entirely footless, and the nature of the generative organ is suspended from there and lies there in position.
διὸ καὶ ἐν τῇ ὁμιλίᾳ ἡ σύντασις γίνεται τῶν σκελῶν· τό τε γὰρ ὄργανον νευρῶδες καὶ ἡ φύσις τῶν σκελῶν νευρώδης.
Therefore, in copulation, a coordination of the legs takes place; for both the organ is sinewy and the nature of the legs is sinewy.
ὥστ’ ἐπεὶ τοῦτ’ οὐκ ἐνδέχεται ἔχειν, ἀνάγκη καὶ ὄρχεις ἢ μὴ ἔχειν ἢ μὴ ἐνταῦθ’ ἔχειν· τοῖς γὰρ ἔχουσιν ἡ αὐτὴ θέσις ἀμφοτέρων αὐτῶν.
So since it is not possible for them to have this, it is necessary that they either do not have testes at all or do not have them in that place; for in those that have them, the position of both of these is the same.
ἔτι δὲ τοῖς γε τοὺς ὄρχεις ἔχουσιν ἔξω διὰ τῆς κινήσεως θερμαινομένου τοῦ αἰδοίου προέρχεται τὸ σπέρμα συναθροισθέν, ἀλλ’ οὐχ ὡς ἕτοιμον ὃν εὐθὺς θιγοῦσιν, ὥσπερ τοῖς ἰχθύσιν.
Furthermore, in those that have the testes externally, the semen advances after being collected because the generative organ is warmed by the movement, and it is not ready immediately upon contact, as it is in fish.
πάντα δ’ ἔχει τὰ ζῳοτόκα τοὺς ὄρχεις ἐν τῷ πρόσθεν ἢ ἔξω, πλὴν ἐχίνου· οὗτος δὲ πρὸς τῇ ὀσφύϊ μόνος, διὰ τὴν αὐτὴν αἰτίαν δι’ ἥνπερ καὶ οἱ ὄρνιθες.
And all viviparous animals have the testes in the front part or externally, except the hedgehog; but this alone has them near the loin, for the very same cause as birds.
ταχὺν γὰρ ἀναγκαῖον γίνεσθαι τὸν συνδυασμὸν αὐτῶν· οὐ γὰρ ὥσπερ τὰ τετράποδα ἐπὶ τὰ πρανῆ ἐπιβαίνει, ἀλλ’ ὀρθοὶ μίγνυνται διὰ τὰς ἀκάνθας.
For it is necessary that their copulation be rapid; for they do not mount upon the back like other quadrupeds, but they copulate standing upright because of their spines.
δι’ ἣν μὲν οὖν αἰτίαν ἔχουσι τὰ ἔχοντα ὄρχεις, εἴρηται, καὶ δι’ ἣν αἰτίαν τὰ μὲν ἔξω τὰ δ’ ἐντός.
Therefore, the cause for which those that have testes have them, and the cause for which some have them externally and others internally, has been stated.
§1.6ὅσα δὲ μὴ ἔχει, καθάπερ εἴρηται, διά τε τὸ μὴ εὖ ἀλλὰ τὸ ἀναγκαῖον μόνον οὐκ ἔχει τοῦτο τὸ μόριον, καὶ διὰ τὸ ἀναγκαῖον εἶναι ταχεῖαν γίνεσθαι τὴν ὀχείαν· τοιαύτη δ’ ἐστὶν ἡ τῶν ἰχθύων φύσις καὶ ἡ τῶν ὄφεων.
On the other hand, those that do not have them, as has been said, do not have this part both because of the fact that they exist not for the better but only for the necessary, and because it is necessary for their copulation to be rapid; and such is the nature of fish and of snakes.
οἱ μὲν γὰρ ἰχθύες ὀχεύουσι παραπίπτοντες καὶ ἀπολύονται ταχέως.
For fish copulate by gliding alongside each other and separate quickly.
ὥσπερ γὰρ ἐπὶ τῶν ἀνθρώπων καὶ πάντων τῶν τοιούτων ἀνάγκη κατασχόντας τὸ πνεῦμα προΐεσθαι τὴν γονήν· τοῦτο δ’ ἐκείνοις συμβαίνει μὴ δεχομένοις τὴν θάλατταν, εἰσὶ δὲ εὔφθαρτοι τοῦτο μὴ ποιοῦντες.
For just as in the case of men and all such animals it is necessary to emit the semen while holding the breath, so this happens to them while they do not take in the sea, and they are easily destroyed if they do not do this.
οὔκουν δεῖ ἐν τῷ συνδυασμῷ τὸ σπέρμα πέττειν αὐτούς, ὥσπερ τὰ πέζὰ καὶ ζῳοτόκα, ἀλλ’ ὑπὸ τῆς ὥρας τὸ σπέρμα πεπεμμένον ἀθρόον ἔχουσιν, ὥστε μὴ ἐν τῷ θιγγάνειν ἀλλήλων ποιεῖν, ἀλλὰ προΐεσθαι πεπεμμένον.
Therefore, they do not need to concoct the semen during copulation, like terrestrial and viviparous animals, but they have the semen already concocted in a mass by the season, so that they do not make it while touching each other, but emit it already concocted.
διὸ ὄρχεις οὐκ ἔχουσιν, ἀλλ’ εὐθεῖς καὶ ἀπλοῦς τοὺς πόρους, οἷον μικρὸν μόριον τοῖς τετράποσιν ὑπάρχει περὶ τοὺς ὄρχεις.
Therefore, they do not have testes, but straight and simple passages, like the small part that exists around the testes in quadrupeds.
τῆς γὰρ ἐπαναδιπλώσεως τοῦ πόρου τὸ μὲν ἔναιμον μέρος ἐστὶ τὸ δ’ ἄναιμον, ὃ δέχεται καὶ δι’ οὗ ἤδη σπέρμα ὂν πορεύεται, ὥσθ’ ὅταν ἐνταῦθα ἔλθῃ ἡ γονή, ταχεῖα καὶ τούτοις γίνεται ἡ ἀπόλυσις.
For of the doubling back of the passage, one part is blooded and the other is bloodless, which receives and through which the semen, already being such, travels, so that when the semen comes there, the emission becomes rapid for these animals too.
τοῖς δ’ ἰχθύσι τοιοῦτος ὁ πόρος πᾶς ἐστὶν οἷος ἐπὶ τῶν ἀνθρώπων καὶ τῶν τοιούτων ζῴων κατὰ τὸ ἕτερον μέρος τῆς ἐπαναδιπλώσεως.
But in fish, the whole passage is such as it is in men and such animals at the other part of the doubling back.
§1.7οἱ δὲ ὄφεις ὀχεύονται περιελιττόμενοι ἀλλήλοις, οὐκ ἔχουσι δ’ ὄρχεις οὐδ’ αἰδοῖον, ὥσπερ εἴρηται πρότερον, αἰδοῖον μὲν ὅτι ὀυδε σκέλη, ὄρχεις δὲ διὰ τὸ μῆκος, ἀλλὰ πόρους, ὥσπερ οἱ ἰχθύες·
And snakes copulate by coiling around each other, but they do not have testes or a generative organ, as has been said before—a generative organ because they have no legs, and testes because of their length—but they have passages, just like fish.
διὰ γὰρ τὸ εἶναι αὐτῶν προμήκη τὴν φύσιν, εἰ ἔτι ἐπίστασις ἐγίγνετο περὶ τοὺς ὄρχεις, ἐψύχετ’ ἂν ἡ γονὴ διὰ τὴν βραδυτῆτα.
For because their nature is elongated, if there were further a delay around the testes, the semen would be cooled because of the slowness.
ὅπερ συμβαίνει καὶ ἐπὶ τῶν μέγα τὸ αἰδοῖον ἐχόντων· ἀγονώτεροι γάρ εἰσι τῶν μετριαζόντων διὰ τὸ μὴ γόνιμον εἶναι τὸ σπέρμα τὸ ψυχρόν, ψύχεσθαι δὲ τὸ φερόμενον λίαν μακράν.
This is just what happens also in the case of those who have a large generative organ; for they are less fertile than those of moderate size, because cold semen is not generative, and that which is carried too far is cooled.
δι’ ἣν μὲν οὗν αἰτίαν τὰ μὲν ὄρχεις ἔχει τὰ δ’ οὐκ ἔχει τῶν ζῴων, εἴρηται·
Therefore, the cause for which some animals have testes and others do not has been stated.
περιπλέκονται δ’ ἀλλήλοις οἱ ὄφεις διὰ τὴν ἀφυΐαν τῆς παραπτώσεως.
And snakes entwine around each other because of the awkwardness of aligning side-by-side.
μικρῷ γὰρ προσαρμόττοντες μορίῳ λίαν μακροὶ ὄντες οὐκ εὐσυνάρμοστοί εἰσιν· ἐπεὶ οὖν οὐκ ἔχουσι μόρια οἷς περιλήψονται, ἀντὶ τούτων τῇ ὑγρότητι χρῶνται τοῦ σώματος, περιελιττόμενοι ἀλλήλοις.
For being very long, they are not easily aligned when trying to fit together at a small part; since, therefore, they do not have limbs with which to embrace, instead of these they make use of the flexibility of their body, coiling around each other.
διὸ καὶ δοκοῦσι βραδύτερον ἀπολύεσθαι τῶν ἰχθύων, οὐ μόνον διὰ τὸ μῆκος τῶν πόρων ἀλλὰ καὶ διὰ τὴν περὶ ταῦτα σκευωρίαν.
Therefore, they also seem to separate more slowly than fish, not only because of the length of the passages but also because of the complexity of this posture.