Crab-, I.ob.st-r>. Shrimps, Barnacles. - 69 



food, while the jaws proper are employed for biting and chewing. Behind 

 the foot-jwas we find five pairs of walking-legs , the first thre? pairs 

 of which end in pinching claws. The claws of the first pair of these 

 walking-legs are of immense size and strength, and serve as weapons of 



Fig. lB'2. Homarus cuJyaris, 1 / 3 nat. size. 



attack or defence. The tail also bears a pair of limbs on each joint; they 

 are termed the swimming-legs, but serve in the female Lobster to carry 

 the eggs. 



If we observe the Lobster more carefully, it seems to be constantly 

 fanning itself with the feathery tassels on its foot-jaws , and often per- 

 forms similar movements with its abdominal legs. This is its method of 

 breathing. Just as man renews the air in his lungs by the contraction 

 and expansion of his chest, so the Lobster , by these movements of its 

 feet, causes fresh water to flow to its gills, which lie under its shell at 

 the base of the legs. Another noticeable action is the constant twitching 

 of the smaller pair of feelers ; these probably serve as olfactory organs, 

 while the larger ones are the organs of touch. 



An important event in the life of a crab or lobster is the annual 

 moult, when the animal literally creeps out of its shell, or as one might 

 say: jumps out of its skin . At these periods a crack makes its ap- 

 pearance .at the hind end of the carapace, and through this the Lobster 

 has to work its way out: first the tail , and then the head and body, 

 being withdrawn from the old shell. It is a troublesome and often dangerous 

 operation, as all the appendages have to be drawn out, including the 

 large claws, the eyes, the antennae and the jaws ; even the wall of the 

 stomach has to be renewed ! Often the animals have tho sacrifice one or 

 both claws , and they are in great danger until the new covering has 

 hardened sufficiently; so they instinctively seek a place of retreat during 

 this operation. Uninjured specimens which have just shed their skin, look 

 very handsome in their new and bright apparel. 



