170 SECRETS OF ANIMAL LIFE 



drinking drops of dew. If we catch one by the leg 

 it surrenders it instantaneously and stalks away. 

 The same sort of profitable autotomy is exhibited 

 by some spiders and by some insects, such as 

 grasshoppers, crickets, and their relatives. A quaint 

 case is that of the Termites, or white ants, which 

 shed their wings when they settle down, after their 

 so-called " nuptial flight." The amputation in all 

 these cases is rapid and reflex, and there is no 

 bleeding. But precise knowledge of the physiology 

 of autotomy is far to seek except in the case of 

 the higher Crustaceans, to which we shall now pass 

 with special reference to the recent work of Mr. J. 

 Herbert Paul. 1 



( i ) It has been recorded in regard to a common 

 amphipod Crustacean, called Gammarus, that if a 

 leg be injured the animal bites it down to the base 

 a quaintly deliberate autophagy. (2) If a prawn's 

 leg be violently seized, the animal gives a vigorous 

 jerk with its tail and the leg breaks off at the base 

 between the second and third joint. If the breakage 

 fails, the prawn may be seen to tug at the limb 

 with its jaws, thus harking back towards autophagy. 

 (3) If the leg of a lobster or crayfish be seized, it 

 always breaks at the level of a groove in the third 

 basal segment. There is a definite breaking-plane. 

 Moreover, before the animal strikes with its tail, a 

 muscle in the third joint weakens the limb at the 

 level of the breaking groove by pulling inwards 



1 Proc. Royal Soc. Edinburgh, xxxv. (1918), pp. 78-94, 4 

 plates, and pp. 232-262, 29 figs. 



