42 THE NATURAL HISTORY OF THE COMMON CRAYFISH. 



what the young are ; but if we examine it more closel}-, 

 especially with a magnifying-glass, we see with pleasure 

 that the little crayfish are already perfect, and resemble 

 the large one in all respects. When the mother of these 

 little crayfish, after they have begun to be active, is quiet 

 for a while, they leave her and creep about, a short way 

 off. But, if they spy the least sign of danger, or there is 

 any unusual movement in the water, it seems as if the 

 mother recalled them by a signal ; for they all at once 

 swiftly' return under her tail, and gather into a cluster, 

 and the mother hies to a place of safety with them, as 

 quickly as she can. A few clays later, however, they 

 gradually forsake her." * 



Fishermen declare that " Hen Lobsters " protect their 

 young in a similar manner, t Jonston,t who wrote in 

 the middle of the seventeenth centmy, says that the little 

 crayfish are often to be seen adhering to the tail of the 

 mother. Roesel's observations imply the same thing ; 

 but he does not describe the exact mode of adherence, 

 and I can find no observations on the subject in the 

 works of later writers. 



It has been seen tliat tlie eggs are attached to the 

 swimmerets by a viscid substance, which is, as it were, 

 smeared over them and the hairs with which they are 



* " Der Monatlich-herausgegeben Insecten Beluitigung." Dritter 

 Theil, p. 336. 1755. 



t Bell's " British Crastacea," p. 249. 



J " Joannis Jonstoni Historia3 naturalis de Piscibus et Cetis Libii 

 quinque. Tomus IV. ' De Cammaro seu Astaco fluviatili.'" 



