June i, 1893] 



NA TURE 



J 05 



is carried with less muscular effort when curled over the 

 back than when stretched out behind as in Euscorpius. 



When attempting to climb up the smooth sides of their 

 box the Parabuthus would raise themselves upon the 

 extremity of the fifth segment of the tail, and by keeping 

 this organ perfectly rigid and in the same straight line 

 as the body they could maintain themselves in a nearly 

 vertical position, thus reaching considerably higher than 

 if supported upon the hind legs alone. 



The method of digging shallow pits or holes in sand, 

 which Mons. Becker and Prof. Lankester have described 

 in the case of Prionurus, is also practised by Parabuthus. 

 Standing upon the first and fourth pairs of legs, and using 

 the tips of the chela? and the end of the tail as additional 

 props, with the disengaged legs a scorpion rapidly 

 kicks the sand backwards between the legs of the last pair, 

 very much as a rabbit or rat does when burrowing. Then 

 with the apparent intention of removing what would 

 prove an obstacle to its vision when crouching in the 

 hole, it sweeps aside with its tail the heap of sand that 

 has been thrown up, until the area surrounding its 

 lurking place is tolerably level. 



I never saw a Euscorpius digging in the sand. They 

 were usually to be found during the daytime under pieces 

 cjf wood, to which they were nearly always clinging 

 belly uppermost. It is difficult to explain why this atti- 

 tude should be assumed. Many terricolous arthropods, 

 however, have the same habit, and I see no reason for 

 thinking that in the case of Euscorpius it has any 

 connection with the copulation of these animals as 

 Prof Lankester suggests. 



All scorpions appear to be carnivorous, and there 

 seems to be little doubt that they live principally upon 

 insects or other articulated animals. My specimens of 

 Euscorpius would eat blue-bottles and small flies, small 

 cockroaches(i?..o-^r/«a«/i,7«), wood-lice, small spiders, and 

 centipedes (Lithobiiis and Geophilus). The Parabuthus 

 were fed principally upon the common house -cockroach 

 and upon blue-bottles. It is interesting to note in con- 

 nection with this last fact that Prof. Lankester's exam- 

 ples of Prionurus would not eat this common cockroach, 

 nor did they seem to care for blue-bottle flies. This 

 difference of instinct in the choice of food is remarkable, 

 seeing how similar these two scorpions are in other 

 particulars, both of habit and structure. 



No one acquainted with the agility of a cockroach and 

 the usual sluggishness of a scorpion would think that the 

 latter would often succeed in capturing the former. Yet 

 in truth, when placed in the same box, the insect seldom 

 has a long lease of life. Its ultimate fate is always due 

 to its ignorance of the scorpion's nature, and to the 

 latter's adroitness in seizing anything that comes within 

 reach. Wandering round the box, and exploring every 

 inch of its new quarters with its antennae, the cockroach 

 soon discovers the presence of the scorpion by touching 

 it with the tips of these organs. The scorpion's sense of 

 touch, however, is as delicate as the insect's, and the 

 latter's antennae, or any part of it that happens to be 

 near, is quickly seized by the pincers of the scorpion. 

 Should the latter be disinclined for food and take no 

 notice of the cockroach's first approach, the insect, 

 continuing its wanderings, will fearlessly creep over the 

 scorpion, just as a rabbit will over a python. Obviously 

 this fearlessness must prove its destruction in the end, if 

 not immediately. By means of its agility and strength, 

 a cockroach sometimes eludes the scorpion's first clutch, 

 and sometimes, but not often, breaks away from the 

 latter's hold. But it does not readily learn from its 

 narrow escape the advisability of giving its enemy a wide 

 berth the next time they meet. 



Although usually trusting to their heels for escape, 

 cockroaches occasionally resort to a method of self- 

 defence which is sufficiently curious to be described. 

 Advancing upon an adversary rear end foremost, and at 



NO. I 23 I, VOL. 48] 



the same time wagging from side to side this region of 

 the body, they deliver vigorous backward kicks with 

 their spiny hind-legs. This novel and humiliating mode 

 of fighting, although not likely to prevail long against 

 jaws and stings, is sufficient, nevertheless, to gain some- 

 times for the insects a temporary reprieve. I have 

 indeed seen a fine female Madeira tarantula spider 

 retreat in discomfiture before a big cockroach of the 

 same sex, which assaulted her in the way described. 



As soon as a cockroach is seized the use of the scorpion's 

 tail is seen ; for this organ is brought rapidly over the 

 latter's back, and the point of the sting is thrust into the 

 insect. The poison instilled into the wound thus made, 

 although not causing immediate death, has a paralysing 

 effect upon the muscles, and quickly deprives the insect 

 of struggling powers, and consequently of all chance of 

 escape. If the insect, however, is a small one, one in 

 fact that can be easily held in the pincers and eaten 

 without trouble while alive, a scorpion does not always 

 waste poison upon it. Thus I have seen a Parabuthus 

 seize a blue-bottle fly, transfer it straight to its mandibles, 

 and pick it to pieces with them when still kicking, Prof. 

 Lankester only rarely saw his scorpions feed. I was more 

 fortunate and repeatedly watched the operation, which 

 is always performed exactly as this author has described. 

 An insect is literally picked to pieces by the small chelate 

 mandibles, these two jaws being thrust out and retracted 

 alternately, first one and then the other being used. 

 The soft juices and tissues thus exposed are drawn into 

 the minute mouth by the sucking action of the stomach. 

 It would seem, however, that some hard chitinous pieces 

 are also introduced into the alimentary canal, for the 

 entire exoskeleton of a cockroach is rarely, if ever, left 

 after the meal is finished. 



Feeding is a slow process ; a good-sized cockroach 

 will last a Parabuthus for upwards of two hours 

 or more. But although voracious eaters when the 

 chance presents itself, they are able to endure with 

 impunity starvation of several weeks' duration. Unlike 

 spiders, which are notoriously thirsty creatures, scorpions 

 never seem to need anything to drink. At least none of 

 mine were ever seen to touch water, although a supply of 

 it was at first always kept in their box. 



With regard to the higher senses, the only one that 

 seems to be highly developed is that of touch. Mons. L. 

 Becker declares that sight and hearing are excessively 

 developed ; but I cannot substantiate this statement in 

 either particular. With regard to hearing, my observations 

 agree entirely with those of Prof. Lankester, who could 

 not detect the existence of any sense of this nature. None 

 of my scorpions ever gave the slightest response to any 

 kind of sound, although they were tried with tuning 

 forks of varying tone and with shouts of both high and 

 low pitch. These animals, in fact, resemble the hunting 

 spiders in being apparently devoid of auditory organs. 

 They further resemble them in the development of their 

 visual powers, being able to see a moving body, like a 

 living cockroach, at a distance of only about three or four 

 inches. Even at a distance less than this they do not 

 seem able to distinguish form. Thus a specimen of 

 Parabuthus excited by the presence of cockroaches in 

 the box, was seen to rush at one of its fellows that crossed 

 its line of vision about two inches off, evidently not 

 recognising by sight a member of its own species, for 

 directly the pincers came in contact with the latter the 

 mistake was discovered, the pugnacious attitude dropped, 

 and no further notice was taken. This last observation 

 shows that more is learnt from the sense of touch than 

 from that of sight, an inference which is further supported 

 by the habit, above referred to, of carrying the pincers 

 well in front of the head as if to feel the way. There is 

 no doubt that the external organs of touch in scorpions 

 are the hairs which thickly or sparingly cover various 

 parts of the body. The tail is often very thickly studded 



