4. Those with this weapon have no small external teeth, for flies draw blood by touching with this organ, and gnats sting with it. Some insects also have stings, which are either internal, as in bees and wasps, or external, as in the scorpion. This last is the only insect that has a long tail; it has claws, and so has the little scorpion-like creature[139] found in books. The winged insects, in addition to other parts, have wings. Some have two wings, as the flies; others four, as the bees; none of the diptera have a caudal sting. Some of the winged insects have elytra on their wings, as the melolontha; and others no elytra, as the bee. Insects do not direct their flight with their tail, and their wings have neither shaft nor division. [139] Phalangium Cancroides. _Linn. Schneider._ 5. Some have a horn before their eyes, as the psychæ[140] and carabi. Of the jumping insects, some have their hind-legs larger; others have the organs of jumping bent backwards, like the legs of quadrupeds. In all, the upper part is different from the lower, like other animals. [140] Butterfly. 6. The flesh of their bodies is neither testaceous nor like the internal parts of testacea, but between the two. Wherefore, also, they have neither spine nor bone, as the sepia; nor are they surrounded with a shell. For the body is its own protection by its hardness, and requires no other support; and they have a very thin skin. This is the nature of their external parts. 7. Internally, immediately after the mouth, there is an intestine which in most insects passes straight and simply to the anus, in a few it is convoluted; these have no bones nor fat, neither has any other exsanguineous animal. Some have a stomach, and from this the remainder of the intestine is either simple or convoluted, as in the acris.[141] The tettix (grasshopper) alone of this, or any other class of living creatures, has no mouth; but, like those with a caudal sting, it has the appearance of a tongue, long, continuous, and undivided, and with this it feeds upon the dew alone. There is no excrement in the stomach. There are many kinds of these creatures, they differ in being greater or less; those called achetae are divided beneath the diaphragm, and have a conspicuous membrane, which the tettigonia has not. [141] Locust. 8. There are many other creatures in the sea which it is not possible to arrange in any class from their scarcity. For some experienced fishermen say they have seen in the sea creatures like small beams, black and round, and of the same thickness throughout; others like shields, of a red colour, with many fins; others[142] like the human penis in appearance and size, but instead of testicles they had two fins, and that such have been taken on the extremity of grappling irons. This is the nature of the internal and external parts of all animals of every kind, both those which are peculiar to certain species, and those which are common to all. [142] Perhaps Pennatula.