THE LOBSTER. 133 



have a pretty good idea of the exo-skeleton, or hard 

 outside part of the lobster, and we shall look next at 

 the soft parts inside. The month seems a very good 

 place to begin at, and yon will find it between the man- 

 dibles, or jaws (Fig. 116). In front of it is a lip shaped 

 like an escutcheon, and it is called the labrum, which 

 means lip. At the back of the mouth is another lip, 

 the metastoma, from two words, which mean beyond the 

 mouthy and this has. been looked upon as the lower lip. 

 The mouth, as in the mussel, opens into a gullet, or 

 oesophagus (Fig. 116), and this into a four-cornered 

 box — the stomach — which is very curiously made. Near 

 the centre of the box, or stomach, the walls come al- 

 most together, dividing it into two parts : the front 

 part is the larger, and it is called- the cardiac end, be- 

 cause in the human heart the upper end of the stom- 

 ach points toward the heart, hence it is called the heart, 

 or cardiac end ; but you see in the lobster it points 

 away from the heart. It contains three strong colored 

 teeth, fastened to a T-shaped frame (Fig. 117), and 

 worked by muscles which are fastened to the inside of 

 the breastplate (carapace). These teeth meet in the 

 middle of the stomach, and form a powerful grinding 

 machine, which crushes the food like the stones in a 

 mill (Fig. 118). Often when you find the empty shell 

 of the lobster on the sea-shore, you can see a perfect 



