THE H/VBITS OF SOxME SCOfiPIONS. 457 



movement is very steady, giving the impression of sometHng on 

 wheels, and is never rapid — never so rapid as to escape a man's 

 complete control. Tliey could be handled with impunity if 

 rapidly seized by the last joint of the tail ; but if slowly 

 approached, a vigorous stroke was delivered at the approaching 

 object by the tail, directed so as to give the sting effect. Com- 

 plete directive power exists in regard to these movements of the 

 tail. The blow can be delivered either straight forwards over 

 the head, straight backwards, or to the right or to the left. In 

 this particular species the tail is relatively far larger and more 

 powerful than in any other Scorpion, and its blows (as tested 

 against a piece of wood) are of very great strength. 



Capture of Prey. — I had some difficulty in feeding these 

 Scorpions. They appeared not to care for such small game as 

 blowflies. Some newly-born white mice were appreciated by two 

 out of the five ; and they all took, at difi"erent times, the large 

 ship's cockroaches which were placed in quantity in the cage with 

 them, though they would not touch the common blackbeetle. 

 They never fed excepting at dusk or in the night ; so that it 

 was diflScult to observe their proceedings. But on two occasions 

 I saw cockroaches attacked. Probably the Scorpion never 

 pursues its prey, but comes upon it by stealth. The cockroaches 

 walked unsuspectingly up to the Scorpion when I was observing 

 the cage with a light just after dark, and suddenly one was 

 seized by the large left chela of the Scorpion; at the same 

 moment the sting was swiftly brought over the Scorpion's head, 

 and two stabs in quick succession were administered to the 

 cockroach *. The Scorpion then carried off its prey, holding it 

 in the large chela. Having found a quiet place in which to feed, 

 the Scorpion tore off the head of the cockroach by means of its 

 chelae, and then inserted the chelicerce into the soft substance of 

 its prey. The struggles of the cockroach had lasted about two 

 minutes ; and not until they had ceased did the Scorpion release 

 the hold of it by his large chela and commence the feeding opera- 

 tion. When now disturbed the Scorpion did not carry his food 

 by means of one of the large chelae as before, when that food 

 was still alive and struggling. Now he carried the dead cock- 



* The poison-gland of the Scorpion is double : each gland is invested by a 

 powerful muscle, the contraction of which expels the poisonous secretion. I 

 have studied the structure of the Scorpion's sting and poison-gland by means of 

 sections prepared for me by my assistant, Mr. A. G. Bourne, B.Sc. 

 LIKN. JOUBN. — ZOOLOGY, VOL. XVI. 34 



