SCORPIONWJE. 



323 



from a branchiate form, and have acquired their trachea 

 independently; apart from the trachea, few structural 

 resemblances to Insects are apparent. 



Order 1. Scorpionim:. 



Scorpions are elongated Arachnoids, restricted to warm 

 countries, lurking under stones or in holes during the day, 

 but active at night. The 

 Scorpio afer of the East Indies 

 attains a length of 6 inches, 

 but most are much smaller. 

 They feed on insects, spiders, 

 and other small animals. The 

 "tail," with the venomous sting 

 at its tip, is usually curved over 

 the anterior part of the body, 

 and can reach forward to kill 

 the prey caught by the anterior 

 appendages, or can be suddenly 

 straightened to strike back- 

 wards. When man is stung, 

 the poison seems to act chiefly 

 on the red blood corpuscles, 

 and, though never or very rarely 

 fatal, may cause much pain. It 

 has been said that scorpions 

 commit suicide when sur- 

 rounded by fire or otherwise 

 fatally threatened, but it has 

 been answered that they do 

 not sting themselves, that they 

 could not if they would, and that, even if they could, the 

 poison would have no effect ! 



The body is divided into — (1) a cephalothorax or "pro- 

 soma" of six segments, whose terga fuse into a carapace, 

 and (2) an abdomen, which includes a broad seven- 

 segmented " mesosoma," and a narrow five-segmented 

 " metasoma." At the end of the latter there is a post-anal 

 curved spine or " telson," containing a paired, compressible 

 poison gland opening at the sharp tip. There is a strong 



Fig. 140.— Scorpion. 

 ch. t Chelicerse; pp., pedipalps ; o., 

 genital operculum; p., pectines ; 

 s., stigma of a lung-book on the 

 pre-abdomen ; st. , sting or post- 

 anal piece. 



