xii HABITS EXTERNAL STRUCTURE 30 I 



and presently both would disappear into the newly -formed 

 retreat. 



After mating, the male was often devoured by tin- female. 

 Moreover, after any combat with an enemy, such as a Li/rn*,/ or a 

 ^D/iijii't/i/ra, it appeared to be de rig-u.rur to eat the vaii(|iiished, 

 and on such occasions only was any considerable amount of food 

 consumed. 



The scorpions were not, however, anxious to fight, greatly 

 preferring to retire if possible ; but when incited to comljat, their 

 sting was quickly fatal to any mature insect, to spiders and to 

 centipedes. Curiously enough, however, insect larvae, though 

 badly wounded, did not succumb to the poison. Newly -hatched 

 scorpions mounted on the mother's back, where they remained 

 motionless for a \veek, entirely unfed. They then underwent 

 a moult, after which they were able to forage for themselves. 



External Structure. 



The chitinous plates of the prosoma are fused to form a 

 carapace. Six segments are clearly indicated by the six pairs of 

 appendages, but, though the development of 8<'<>r/>i affords little 

 direct evidence of the fact, there is reason to believe that there 

 once existed a pre-cheliceral segment, 1 as has been clearly proved 

 in the case of the spiders. An embryonic pregenital segment 

 has also been recognised. The six prosomatic appendages are 

 those proper to the Arachnida, being the chelieerae, pedipalpi. 

 and four pairs of ambulatory legs. The mesosoma, which is 

 broadly attached to the prosoma, comprises six segments, in- 

 dicated ventrally by the genital operculum, the peelines, and the 

 four pairs of pulmonary stigmata. The last of the broad ab- 

 dominal segments, which tapers abruptly, belongs to i he metasoma, 

 which also comprises six segments, and is succeeded by the 

 post-anal spine or sting. 



PrOSOma. Near the middle of the carapace are two median 



eyes, and on its antem-lateral borders are usually to be found 

 groups of smaller eyes, numbering from two to five. All the eyes 

 are simple. Then: is a difference, however, in their de\ elopmeiil . 

 the median eyes being diplostichou*, oi involving two layers of 

 hypoderm, while the lateral eyes arc monostichous, and p 

 through a stage strikingly like the permanent condition of the 



1 Brauur, Zcit-lu-. fisy. /"!. lix., 1 >'.".">. \>. 



