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The most cliaracteristic feature of spiders is their spinning organs. 

 The silk is secreted in glands within tlie abdomen ; and while in the 

 body it is a fluid. It passes out through the spinnerets, which are 

 situated near the hind end of the abdomen. There are two or three 

 pairs of spinnerets. These are more or less linger-like in form, and 

 sometimes jointed (Fig. 123). Upon the end of each spinneret 

 there are many small tubes, the smnning tubes (Fig. 124), from 

 which the silk is spun. Some spiders have as many as one hundred 

 and fifty or two hundred of these spinning tubes on each spinneret. 



Ordinarily the tips of the spinnerets are brought close together, 

 so that all of the minute threads that emerge from the numerous 

 spinning tubes unite to form a single thread. Hence this tiny 

 thread, which is so delicate that we can see it only when the lioflit 

 falls on it in a favorable way, is composed of hundreds of threads. 

 It is not like a rope, composed of separate strands; for all the 

 minute threads fuse together into a single thread. The change in the 



..?"■> 



123. — Spinnerets of a 124. — A 1 2o. — T Isci d silk 1 26. — Sp inner eta 

 spider. gi^oup of -from an orb- and cnbellam 

 spinning tceb. of a curled- 

 tubes, thread tceaver. 



silk from a fluid to a solid cord, strong enough to support the weight of 

 the spidei*, must take place quickly after the silk comes in contact with 

 the air on leaving the spinning tubes ; the minute size of the threads 

 coming from the spinning tnbes doubtless facilitate this change. 



Sometimes a spider will spread its spinnerets apart, and thus spin 

 a broad ribbon-like band. AVe have seen a spider seize a large 

 grasshopper M'liich was entangled in its web, and rolling it over two 

 or three times, completely env^elop it in a sheet of silk spun from 

 its spread apart s[)innerets. AVe have already described bands spun 

 by orb weavers across the hub of the net in this way. 



It is su})posed that the two kinds of silk spun by the orb weavers 

 are spun from difl:erent spinnerets, and that the viscid silk comes from 



336 



