124 COMPARATIVE ANATOMY AND PHYSIOLOGY. 



From the appendage next behind, or first pair 

 of maxillae, the outer branch, or exopodite, is 



still absent, but the basal portion is well developed, 

 though not so stout or so strong as in the case of the 

 mandible ; both its joints are flattened out and pro- 

 vided with a number of bristles, which are also present, 

 though less numerous and not so strong on the un- 

 jointed piece which represents the endopodite. So 

 far as the digestive process is concerned, the second 

 pair of maxilla* are still chiefly represented by 

 the two basal joints of the typical appendage, the 

 endopodite being still small and undivided, while the 

 exopodite, though developed, has duties to perform 

 in relation to the respiratory organs. (See page 225.) 

 Behind the maxillae we find three pairs of maxil- 

 lipedes, or foot-jaws, the most posterior of which is 

 the largest, and in a state of repose covers over the 

 five pairs of mouth organs that lie in front of it. In 

 the two more posterior pairs we do not observe that 

 increase in size or flattening out of the basal portion 

 which we saw in the maxillae ; but in the first 

 maxillipede the most important part is taken by 

 the two lamellar joints, of which that portion is 

 composed, while the endopodite consists only of two 

 in the place of the five distinct joints which are found 

 in the succeeding pairs. 



All these appendages are so articulated to the 

 walls of the body that they work on one another from 

 side to side ; it is clear that they can only cut or tear 

 the food 011 which the great forceps have already 

 seized, and, for the purposes of digestion, the food has 

 to undergo a further comminution, comparable in a 

 sense to that which is performed by the grinding, as 

 distinguished from the cutting teeth of man. 



The mouth, which is a narrow elongated slit, leads 

 by a short wide gullet into a capacious stomach, 

 divided into an anterior and a posterior chamber, and 



