Chapter XIII.

1. We must now treat of the mode of reproduction, both of those animals which use sexual intercourse, and those which do not; and, first of all, we will speak of the testacea, for this is the only entire class which is not reproduced by sexual intercourse. The purpuræ collect together in the spring, and produce what is called their nidamental capsules (melicera), for it is like honey-comb, though not so deeply cut, but, as it were, made up of the white pods of vetches. These capsules have neither opening nor perforation, nor are the purpuræ produced from them; but both these and other testacea are produced from mud and putrefaction. But this substance is an excrementitious matter both in the purpura and the ceryx, for these last also produce similar capsules.

2. The testacea which produce these capsules are generated in the same way as the rest of their class, but more readily when there are homogeneous particles pre-existing among them; for, when they deposit their nidamental capsules, they emit a clammy mucus, from which the scales of the capsules are formed. When all these have been deposited, they emit upon the ground a sort of chyle, and small purpuræ spring up upon the same spot and adhere to the larger purpuræ, though some of these can hardly be distinguished by their form. But if they are taken before the breeding season, they will sometimes breed in the baskets, not indeed anywhere, but they collect together like they do in the sea, and the narrow limits of their place of captivity make them hang together like bunches of fruit.

3. There are many kinds of purpuræ, some of which are large, as those which are found near Sigeum and Lectum; and others are small, as those in the Euripus and on the Carian coast. Those found in gulfs are large and rough. Most of them contain a black pigment; in others it is red, and the quantity of it small. Some of the largest weigh as much as a mina. Near the shore and on the coast they are small, and the pigment is red. Those which are natives of the north contain a black pigment; in those of the south it is red, generally speaking.

4. They are taken in the spring, about the time that they deposit their capsules, but they are never taken during the dog-days, for then they do not feed, but conceal themselves and get out of the way. The pigment is contained between the mecon and the neck. The union of these parts is thick, and the colour is like a white membrane; this is taken away. When this is bruised, the pigment wets and stains the hand. Something resembling a vein passes through it, and this appears to be the pigment; the nature of the rest resembles alum.[164] The pigment is the worst at the period of depositing their nidamental capsules.

5. The small ones are pounded up, shells and all, for it is not easy to separate them; but they separate the larger kinds from the shells, and then extract the pigment. For this purpose the mecon is divided from the neck, for the pigment lies above the part called the stomach, and when this is taken away, they are divided asunder. They are careful to bruise them while alive, for if they die before they are cut up, they vomit up the pigment; for this reason they keep them in the baskets till a sufficient number is collected, and there is time to procure the pigment.

6. The ancients did not let down or fasten any basket-net to their baits, so that it often happened that the purpura fell off as they were drawn up; but at the present time they use basket-nets, in order that if the purpura should fall off, it may not be lost. They are most likely to fall off when full, but when empty it is difficult to draw them from the bait. These are the peculiarities of the purpura. The nature of the ceryx is the same as that of the purpura, and so are their seasons.

7. They both have opercula, and so have all turbinated shell-fish, from the period of their birth. They feed by forcing out their tongue, as it is called, beneath the operculum: the purpura has a tongue larger than a finger, with which it feeds upon and pierces the conchylia, and even the shells of its own species. Both the purpura and the ceryx are long-lived, for the purpura lives six years, and its annual increase is seen in the divisions on the helix of its shell.

8. The mya also deposits nidamental capsules; those which are called limnostrea are the first to originate in muddy places, but the conchæ, chemæ, solens, and pectens find their subsistence in sandy shores; the pinnæ grow up from their byssus both in sandy and muddy shores. The pinnæ always contain a pinnophylax, either like a small caris or cancer, and soon die when this is extracted. On the whole, all the testacea are produced spontaneously in mud different kinds originating in different sorts of mud: the ostrea is found in mud, the conchæ and others that have been mentioned in sand. The tethya, balanus, and others which live on the surface, as the patella and nerita, originate in holes in the rocks. All these reach maturity very soon, especially the purpuræ and pectens, for they are matured in one year.

9. Very small white cancri are produced in some of the testacea, especially in the myæ that inhabit muddy places, and next to this in the pinnæ those which are called pinnoteræ; they occur also in the pectens and limnostrea. These animals apparently never grow; and the fishermen say that they are produced at the same time as the creatures they inhabit. The pectens disappear for some time in the sand, and so do the purpuræ. The ostrea (bivalves) are produced in the manner described, for some of them originate in shallow water, others near the shore, or among rocks, or in rough hard places, or in sand; and some have the power of locomotion, others have not.

10. Among those that are not locomotive, the pinnæ are fixed; the solens and conchæ remain on one spot, though not fixed, and do not survive separation from their home. The nature of the aster[165] is so hot, that if it is captured immediately after swallowing anything, its food is found digested; and they say that it is very troublesome in the Pyrrhæan Euripus. Its form is like the paintings of a star. The creatures called pneumones are spontaneously produced. The shell which painters use is very thick, and the pigment is produced on the outside of the shell; they are principally found in the neighbourhood of Caria.

11. The carcinium also originates in earth and mud, and afterwards makes its way into an empty shell, and when it grows too large for that, it leaves it for a larger one, as the shell of the nerita, strombus, and such like; it frequently occurs in the small ceryx. When it has entered the shell, it carries it about and lives in it, except that as it grows it migrates into a larger shell.