LOBSTERS. 27 



herself a walking nursemaid by reason of this little 

 piece of attention to maternal duties. Each pair of 

 appendages is like every other pair ; albeit, you find 

 great variation in their shape and form. Those of the 

 tail (ex en) exist each as a double-leaved structure set 

 on a joint. If you look at the tail-fin, wherewith, aided 

 by the big muscles of the tail, the lobster makes a 

 forcible backward stroke in the water, you will dis- 

 cover that the fin consists simply of a pair of the 

 swimmerets you see further forward on the body, 

 broadened out, and having a little centrepiece (/) set 

 between them. 



Go farther forward on the body and you come to 

 the five pairs of walking legs. Now these legs, after 

 all, are only altered swimmerets, in which the inner- 

 most leaf has grown big and foot-like, and has become 

 encased in a limy shell. Further forward still, and 

 you reach the "foot-jaws," which are half-way houses 

 between jaws in front and legs behind. Then come 

 the jaws proper, of which your lobster boasts three 

 pairs. One pair is hard and thorny, the other two 

 are softer in texture but they are all really swim- 

 merets, like those of the tail. Then in front of the 

 jaws come the " feelers," and of these two pairs (fig. 9, 

 a b) exist. The lesser pair has two divisions, while 

 the greater feelers, that project like huge horns, have 

 only one division or part. These feelers, again, are 

 only modified appendages, all corresponding to the 

 simpler ones of the tail. Finally come the eyes ; and 

 the movable eye-stalks on which the eyes are set, 

 correspond to the single joint by which the appen- 

 dages elsewhere are attached to the body. 



Now, if you ask me, " How one comes to all this 

 certainty of knowledge ? " I reply, because when the 



