ARAN E A 



211 



Effect on the Scorpion. — ^At the present time it is not believed 

 that a scorpion commits suicide when in difficulties by stinging 

 itself in the head with its own sting, because, though not absolutely 

 immune to its own venom, it possesses a high degree of immunity 

 against it. Accidental but not intentional wounding of an indi- 

 vidual by its own sting is said to be known. 



Immunity. — -A natural immunity exists in the jerboa {Jaculus 

 jaculus L.) and in the desert rat {Gerbillus pyramidunt Geoff r.), and 

 a partial immunity in the zerilla {Ictonyx lihyca Ehrenberg), 



According to Balfour, fakirs at times possess an acquired im- 

 munity, but this has not so far been obtained in any animal. Cal- 

 mette has reported that the serum of a horse immunized against 

 cobra-venom can neutralize the venom of Buthus occitanus — a. fact 

 which Metchnikoff has confirmed; but Nicolle and Catouillard have 

 found this serum useless against the venom of the Tunis scorpion 

 {Scorpio maurus). 



Diagnosis.^ — -The history of the case and the single puncture on 

 the affected part makes the diagnosis generally easy. 



Prognosis. — If an adult is stung, the prognosis is good, as death 

 is known to be rare, but not so in children. The prognosis, there- 

 fore, varies with the age, and can be judged by the following table 

 from Bray, quoted by Wilson, which gives the deaths at Omdurman 

 in 1902 as follows: — 



Under one year . . . . . . . . . . 5 



One to five years . . . . . . . . . . 9 



Five to fifteen years . . . . . . . . . . 7 



Total . . . . . . . . ..21 



Deaths of adults, however, are known, but generally take place 

 in a few days, not quickly. 



Treatment. — In the treatment, the first thing to do is to give 

 a full dose of the serum, and then to apply a proximal ligature 

 and to treat the wound with permanganate of potash, as described 

 under the heading of Snake-Bite. 



Washing and bathing with a weak solution of ammonia may also 

 be tried, and stimulants should be given. 



Colonel Duke recommends that 5 to 10 minims of a 5 per cent, 

 solution of cocaine be injected subcutaneously close to the sting in 

 an adult, and i to 5 minims in infants and children. Eucaine or 

 stovaine might be preferable, and can be imported from any 

 chemist in sterile capsules ready for hypodermic injection. Simpson 

 recommends the local application of a paste of ipecacuanha. 



2. Aranea. 



The Aranea, or spiders, are found all over the world, but by far 

 the largest are in the tropics, and their peculiarly repulsive appear- 

 ance has given rise to numerous fables, both ancient and modern, 

 with regard to their poisonous properties. 



