CRUSTACEA. 87 



Ireland, but is generally stated to have been introduced. It 

 is said to be possessed of great longevity: M. Edwards asserts, 

 that it lives for more than twenty years, and continues to 

 grow during that entire period.* It is the office of the males 

 to cater for the female and young; and a very intelligent 

 observer states, that he has frequently seen them catching 

 and brcalving up small fish as their food.t On being dis- 

 turbed, both sexes gather their young under their tails; but a 

 singular ditference prevails between the sexes, with regard to 

 the manner of protecting their progeny. The male, on being 

 lifted, retains them under his tail; but the female, on being 

 captured, wiser than her lord, "slaps" them into the water 

 ■with such force as to produce the etfect of a shower of rain 

 upon the surface. 



Tlie cast-off shell of many of the Crustacea preserves its 

 fonner appearance so completely as to exhibit the form of the 

 animal, and even its most minute appendages. This we have 

 not been so fortunate as to observe, but it is fully confirmed 

 by the following note from Mr. R. Ball, Avho adds, at the 

 same time, some other particulars, illustrative of habits. 

 •' Some years ago, I kept a Cray-fish for a considerable time, 

 in a shallow glass vessel, about twenty inches in diameter, 

 and containing about two inches' depth of Avater. This animal 

 gradually acquired great viciousncss, and would eagerly attack 

 the fino-ers of any one who chose to put them within his 

 range, pursuing the intruding digits round the boundaries of 

 his demesne. After he had been thus a year in my possession, 

 I was one day surprised to see a second Cray-fish iu the vessel; 

 but on taking the intruder in my hand (believing it to have 

 been placed in the vessel by a waggish relative), it proved to 

 be the exuvia; of my old friend, so perfect as to present liis 

 exact counterpart. Instead of his usual boldness, he now 

 exhibited the most remarkable timidity, which continued for 

 three or four days. He was at first quite soft, and appeared 

 considerably larger than usual, but gradually grew firmer, and 

 on the fifth day felt to the touch as hard as usual, and ad- 

 vanced with open pincers to the attack of my finger, though 

 evidently not without some little doubtfulness of his powers. 

 Before the end of the week he was himself again, came on 



• Histoire des Crustacea, tome ii. page 330. 



t These notices of the Cray-lish are entirely extracted from Mr. 

 Thompson's article on the Crustacea, already refeired to. 



