348 



PHYLUM ARTHROPODA. 



Order i. SCORPIONID.K. 



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, 



il "\ / ffl 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 ! 



</*., Chelicerae ; //., pedipalps ; o., The body IS divided into 



genital operculum ; /., pectines., , x 11,1 



s., stigma of a lung-book on the (i) a cephalothorax or ''pro- 



anffplece! **'' * K * osi ~ 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 

 cuticle of chitin, and also an interesting internal piece of 

 skeleton (the endosternite), partly chitinoid, but also 

 resembling fibro-cartilage, which lies in the cephalothorax 



FIG. 170. Scorpion. 



