TEE LOBSTER AND OTHER CRUSTACEANS. 85 



filled with water, in which are suspended grains of sand 

 which find their way into the capsule. A wave of sound 

 disturbs the grains of sand, the vibrations affect the sensi- 

 tive hairs, and thus the impression of a sound is tele- 

 graphed along the main auditory nerve to the brain. 



The fine hairs fringing the mouth-parts and legs are 

 organs of touch. The seat of the sense of smell in the 

 Crustacea is not yet known, but it must be well developed, 

 as nearly all Crustacea are in part scavengers, living on de- 

 caying matter as well as live fish, for the lobster is an ex- 

 pert fisherman, catching dinners, etc. We see, then, how 

 complicated is the body of a lobster; it is an exceedingly 

 active creature, its brain and nervous system are correspond- 



FIG. 88. Freshly hatched Lobster. (Magnified.) 



ingly complex, and its mental traits of no mean order. The 

 creature is a great advance beyond a worm. Crabs also 

 have the power of finding their way back to their original 

 habitat when carried off even for several miles. 



The lobster spawns from March till November. The 

 eggs are attached in bunches to the swimming feet of the 

 hind body. The young (Fig. 88) are hatched with much of 

 the form of the adult, not passing through a series of sin- 

 gular changes, called a metamorphosis, as do most shrimps 

 and crabs. They swim near the surface until about one 

 inch long, afterwards remaining at or near the bottom. 



The lobster, after having nearly grown up, probably 

 moults but once, during midsummer. When about to 



