rrocecdintjs. 67 



it and the glass. We rapped his knuckles whenever we saw 

 him, but directly we sat down to a meal we heard bump, 

 bump against the glass, and he was at it again. 



The life history of Crabs is very curious; the eggs are 

 carried about attached to the swimmerets under the body, as 

 is well known in the Lobster. The young vary somewhat, 

 according to the species, but the Green Crab may be taken as 

 a fair specimen. They were known for many years under 

 the name of Zoea, before one had any idea that they were 

 the young of Crabs, so little do they resemble the adult 

 form. "When first hatched, they have sessile eyes, long tails, 

 and no claws. At the first moult they have claws, stalked 

 eyes, and shorter tail ; at the second the tail is turned under, 

 and at the third it is a perfect Crab, with the stalked eyes set 

 in sockets, within which they can be turned back, and are 

 then fitted for their rough life amongst the rocks. From 

 time to time they continue to throw off their shells, as they 

 become too small for the body inside, the skin of which soon 

 after hardens, and becomes a new shell. When any of their 

 limbs are injured or broken off, they would bleed to death if 

 they had not the extraordinary power of breaking off their 

 limbs near the first joint, which rapidly heals over, and a 

 new limb appears as a bud ; within this a perfect limb is formed, 

 which is liberated at the next casting of the shell, but is 

 generally smaller than the other limbs. The age to which 

 Crabs and Lobsters live is unknown, but they are often found 

 with very old barnacles attached, which shows that it is some 

 years since they last changed their shells. 



One of the most curious Crabs is the Pea Crab, which lives 

 in Mussels and other bivalves, and is so named from its round 

 form. This was a wonder to the ancients, and Aristotle and 

 Pliny relate some curious tales about them. The young pro- 

 bably enter the shell as Zoea, and the females never go out 

 again. Their bodies are soft, and they certainly would be 

 killed if nipped by the mussel whilst attempting to get out ; 

 but the males have very hard and strong shells, and legs 

 covered with hairs, which enable them to swim well, and they 

 go in and out of the Mussels frequently. 



F 2 



