SPIDERS AND MITES. 245 



manner, and open in all of tlic spinnerets. 2. Six lung 

 twisted tubes, which gradually enlarge into as many 

 pouches, and then are each protracted into a very long 

 duct, which forms a double loop. 3. Three pairs of 

 glandular tubes, similar to the preceding, but which 

 open externally through short ducts. 4. Two groups 

 of much branched sacs, whose long ducts run to tlie 

 upper pair of sjjinnerets. 5. Two slightly branched 

 blind-tubes, which terminate by two short ducts in the 

 middle pair of spinnerets. 



It is not very easy to examine the spinnerets with a 

 microscope, so as to make out their structure. If we 

 confine the Spider in a glass cell, it is so restless that 

 the least shock or change of position will cause it to 

 move to and fro ; and, besides, when it does become 

 quiescent, the spinnerets are closed in towards each 

 other, so that we cannot see their extremities. By se- 

 lecting a specimen, however, recently killed, such as 

 this Clubiona, we may discern sufficient to enable us to 

 comprehend their construction. 



Looking, then, at the abdomen from beneath, we 

 see the three pairs of spinnerets clustered together close 

 to the extremity. The pair most forward are shaped 

 somewhat like barrels, whose free ends bend over to- 

 wards each other. They are covered with stiff black 

 hairs, and just within the margin of what may be 

 called the head of the barrel (for it is cut off horizon- 

 tally, with a sharj) rim), there is a circle of \qyj close- 

 set, stiff, whitish bristles, which arch inwards. The 

 whole flat surface of the " head," within this circle of 

 bristles, is beset with very minute horny tubes, stand- 

 ing erect, which are the outlets of the silk-ducts, that 

 belong to this pair. 



