372 ANIMAL DEFENCES 



Though it watched me attentively, the frog remained perfectly- 

 motionless, and this greatly surprised me. When I was sufficiently 

 near to make a grab, it sprang straight at my hand, and, catching 

 two of my fingers round with its fore-legs, administered a hug 

 so sudden and violent as to cause an acute sensation of pain; 

 then, at the very instant I experienced this feeling, it released its 

 hold and bounded out and away." The specimen, however, was 

 captured, but later on managed to escape from the box in which 

 it was imprisoned, and Mr. Hudson failed to secure another 

 individual of the same sort. "That this singular frog has it in 

 its power to seriously injure an opponent is, of course, out of 

 the question; but its unexpected attack must be of great advan- 

 tage. The effect of the sudden opening of an umbrella in the 

 face of an angry bull gives, I think, only a faint idea of the 

 astonishment and confusion it must cause an adversary by its 

 leap, quick as lightning, and the violent hug it administers; and 

 in the confusion it finds time to escape. I cannot for a moment 

 believe that an instinct so admirable, correlated as it is with the 

 structure of the fore-legs, can be merely an individual variation; 

 and I confidently expect that all I have said about my lost frog 

 will some day be confirmed by others. Rana htdator \i.e. the 

 Wrestling Frog] would be a good name for this species." 



Retreat amongr various Invertebrates. — Among- MoUusca we 

 find a very interesting and well-known device for securing a safe 

 retirement when attacked by foes in Cuttle- Fishes and the like. 

 These animals possess an ink-bag (the secretion of which was the 

 original source of the pigment "sepia") from which a dark fluid can 

 be ejected at will. The result is the production of a cloudiness in 

 the water for a considerable distance, under cover of which the 

 Cuttle- Fish commonly manages to beat a successful retreat. Hick- 

 son (in A Naturalist in Celebes') thus describes this proceeding: — 

 "... I often saw advancing slowly over the sea-gardens, in parties 

 of from four to six, a group of cuttle-fish, swimming with an even 

 backward movement, the fringes of their mantles and of their arms 

 trembling, and their colour gradually changing to what seemed to 

 me to be an almost infinite variety of hues as they passed over the 

 various beds of the sea-bottom. Then suddenly there would be 

 a commotion in what was previously a calm and placid scene, the 

 striped and speckled reef-fishes would be seen darting away in all 

 directions, and of the cuttle-fishes all that remained were four or 



