Page:Popular Science Monthly Volume 6.djvu/599

Rh have pincers, or chelæ. Now we have come to the largest pair; the chelæ, or pincers at the ends, are so large and strong that they are called the "great chelæ." They are the lobster's weapons of defense. When he is taken prisoner, that is, seized by one of his claws, he quietly leaves the claw in the hands of his astonished captor, and beats his retreat as fast as possible. He has another odd way of laying down his arms when he is frightened by a great noise, such as thunder, or the tiring of a cannon. It is no uncommon thing to find a number of these broken swords lying about among the rocks, showing where there has been a lobster fright or fight. As soon as one claw goes, another takes its place, but it is some time before the new one gets as long and strong as the old one. You will notice quite a difference between the two large claws, or forceps. In one, the teeth are large and blunt (Fig. 17), and in the other they are very sharp (Fig. 18).

The blunt-toothed pincers the lobster uses as an anchor to moor himself, while with the other he attacks and seizes his prey. So much for the great claws, or chelaæ. The next three pair are called maxillipedes, or foot-jaws, because they act both as teeth and feet (Fig. 15). The hindmost foot-jaw has three divisions. One branch passes up into the side-chamber of the lobster; the middle branch is long and jointed: this, and its fellows on the other side, act as a pair of scissors, cutting the food. The third branch is jointed, and is a walking-leg. The middle foot-jaw (maxillipede) is much like the last, while the front one does not send a piece upward into the side-chamber (Fig. 22), and one of its branches is flattened out, so as to look like leaves. The four walking-legs, the great pincers (chelæ) and the three pair of foot-jaws (maxillipedes), making eight pair in all, belong to the lobster's breast (thorax). Now we come to the head, which is provided with six pair of "hangers-on," or appendages. The two back-pair belonging to the head are called maxillæ, because they lie at the side of the mouth, and are like jaws. The hindmost of the jaws—or maxillæ—on each side has a boat-shaped, or oval plate (Fig. 22), which lies at the front entrance of the side-chamber, about which we will hear more presently. The ends of the front pair of little jaws (maxillæ) are leafy, like those of the front pair of foot-jaws (maxillipedes). Now we come to the jaw itself, or mandible, which has strong teeth, bears a small appendage, the palp, and lies at the side of the mouth. From