CLASS ARACHNLDA. 59 



second pair of appendages are greatly elongated and bear, 

 at their ends, prehensile (pre hen'sii) organs. 



PIG. 93. 



Phaldn'gium dor sa' turn. Daddy-long-legs. 



Closely related, though more generally distributed than 

 the Scorpions, are the " Harvest Men," or "Daddy-long- 

 legs," so common about our gardens, where they are 

 beneficial, feeding on small insects which injure the crops. 



ORDER ARANEIDA (a ra ne'i da). 



The Spiders, like the Scorpions, have the head and 

 thorax united, though the abdomen lacks the marked 

 segmentation, is spherical, and is attached FIG. 



to the cephalo-thorax by a slender pedicel 

 (ped'i sel). The first pair of appendages, 

 the jaws, are provided with openings for 

 the exit of poison, while the second are 

 more foot-like, resembling the remaining 

 four. The most striking peculiarity is the 

 power of web-making. The material for 

 this is secreted as a gluey substance, 

 forced through a series of porous plates 

 situated on the lower side of the abdo- 8pider ' 8 Thread 

 men. The fine threads may unite and form a cable, 

 which quickly hardens in the atmosphere. The Spider 

 may attach the web, and, by moving away, more and 

 more material is pulled through the porous plates, the 



