THE LOBSTER 391 



THE LOBSTER (Family Nephropsid^) 



We must all have noticed that a lobster is characterized by its 

 long horns, mail-clad body, and great claws. 



The skin of a lobster may be considered as an external 

 skeleton, enclosing the body in a kind of natural armour, with 

 many joints and hinges. For, if we examine a lobster's body, we 

 shall see that it is almost as flexible as that of a caterpillar. In 

 spite of its casing of hard shell, it can be folded or doubled up 

 so that the extremity of the tail lies almost underneath the 

 head. 



But the skeleton of a vertebrate animal has another function 

 to fulfil besides that of supporting the body; it has to serve as an 

 attachment for the muscles. All the different movements which 

 we can make are due to the action of our muscles. Now the 

 muscles of a lobster, which possesses no bones, are attached in 

 just the same way to the inner surface of the shell. The larger 

 and more powerful muscles, too, such as those that work the 

 great claws, have a ridge provided for their attachment, just like 

 some of the bones of our own bodies. So that the shell of a 

 lobster really fulfils the office of a skeleton in both respects, as 

 it gives the necessary support to the body, and also serves as an 

 attachment for the muscles. 



In the lobsters and crabs this shell is formed of three separate 

 layers, and is so wonderfully hard that it is often employed for the 

 purpose of sharpening knives. 



At certain seasons of the year the lobster loses all inclination 

 to eat. Taught by instinct, too, it conceals itself in some rocky 

 crevice, in which its enemies are not likely to find it. Its flesh 

 then loses its consistency, its muscles become flabby and powerless, 

 and its body is reduced to the condition known as " watery ". 



After a short time the shell splits, and is gradually thrown off", 

 together with the coating of the horns and the eyes, and even the 

 membrane which lines the stomach. The animal, although already 

 clothed in a new suit of mail, is now extremely soft, and increases 

 rapidly in size, until, after a few hours, it is very much larger than 



