The Lobster. 67 



OUTLINB OF NEW WOBK. 



The abdomen coDsists of rings, and we find but one 

 pair of swimmereta on a ring. Now let us see whether 

 the appendages of the head-thorax are borne on rings, too. 



With strong scissors we cut along the groove of the 

 carapace, from the front half-way up the back, and bend 

 back the carapace, as shown in Fig. 4 , thus displaying 

 the plumy gills, some fastened to the sides of the thorax, 

 others to the legs and the jaw-feet. Cutting away the 

 gills, we see a thin white shell, which seems to be made 

 of several pieces that have grown together. Now, by 

 lifting each leg in turn, we see that every pair of legs is 

 borne on one of these pieces, which are therefore the 

 lower portions of several rings. As we approach the 

 mouth and the appendages become more crowded, the 

 rings are completely grown together, but we conclude from 

 what we have seen that each pair of appendages repre- 

 sents a ring, and the head-thorax therefore consists of 

 fourteen rings soldered together. 



Children mnst not be hurried to this oonclasion, but led np to it 

 slowly and carefully by patient qaestioniog. They will know only 

 what they discover for themselves. 



We have found the gills safely hidden away under the 

 two sides of the carapace, in the lobster's vest-pockets, 

 which are open at each end, so that the water may rui-h 

 out as well as find its way in. But as there must be 

 always a current of water over the gills, a spoon-shaped 

 organ, — the gill-scoop or flabellum (/, Fig. 4), — attached 

 to each of the second maxillaB, is constantly scooping it 

 out at the front of the pockets as fast as it rushes in at 

 the back. In this way a fresh supply of oxygen is con- 

 tinually brought to the blood in the gills. 



A probe put into the mouth passes into the stomach, a 



