BIOLOGY FOR YOUNG BEGINNERS. 581 



have pincers, or chelae. Now we have come to the largest pair ; the 

 chela?, or pincers at the ends, are so large and strong that they are 

 called the " great chelae." They are the lobster's weapons of defense. 

 When he is taken prisoner, that is, seized by one of his claws, he quiet- 

 ly 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 

 lono- 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). 



Fig. 17. Large-toothed Claw. Fig. IS. Small-Toothed Claw. 



The blunt-toothed pincers the lobster uses as an anchor to moor him- 

 self, while with the other he attacks and seizes his prey. So much 

 for the great claws, or chela?. The next three pair are called maxilli- 

 pedes, 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 scis- 

 sors, 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 (chelae) and the three pair of 

 foot-jaws (maxillipedes), making eight pair in all, belong to the lob- 

 ster's breast (thorax). Now we come to the head, which is provided 

 with six pair of " hangers-on," or appendages. The two back-pair be- 

 longing to the head are called maxillae, because they lie at the side of 

 the mouth, and are like jaws. The hindmost of the jaws or maxillae 

 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 (maxillae) 

 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 



