SPIDERS AND MITES __24S 



elaborate than those of the latter. Generally speaking, 

 there are three pairs of spinnerets, or external organs, 

 through which the threads are produced, but in some few 

 cases there are only two pairs, and in others, as the Gar- 

 den Spiders (Epeira), the hindmost pair seem to be united 

 into a single spinneret. These are always situated at the 

 hinder extremity of the body, and I will show them to you 

 presently. First, however, I will describe the internal ap- 

 paratus the source of the threads. 



The glands which secrete the gummy fluid are placed in 

 the midst of the abdominal viscera, and in some instances 

 as in the female of Epeira fasciata, a species which 

 makes a remarkably large web they occupy about a quar- 

 ter of the whole bulk of the abdomen. About five differ- 

 ent kinds of these glands may be distinguished, though 

 they are not all present in every species. The Epeiroe, 

 however, present them all. 



In this genus there are: 1. Small, pear-shaped bags, 

 associated in groups of hundreds, and leading off by short 

 tubes, which are interlaced in a screw-like manner, and 

 open in all of the spinnerets. 2. Six long 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 the upper pair of spinnerets. 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 con- 

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



