170 Transactions of the Society. 



VI. — 0)1 the Threads of Sliders' Webs, 

 By John Anthony, M.D., F.R.M.S., &c. 



(^Eead lUh January, 1882.) 



In the course of observations on the habits of spiders, and more 

 particularly of those which construct geometrical webs, an idea 

 occurred, that by management, the Epeira Diadema — one of the 

 largest of our garden spiders — could be made to spin his thread in 

 such away, as to cause the whole, or the greater part of the strands 

 composing this minute cord or cable, to remain separate, instead of 

 coalescing, and so forming the well-known " thread " by which the 

 diadem garden spider is so often seen suspended. The experiment 

 answered perfectly, and the results were so full of interest for the 

 student of natural history, as to cause me to describe carefully the 

 means I employed, so that any one may be able to repeat the expe- 

 riment, and arrange fairly permanent preparations of the parts 

 making up the spider's thread for dehberate examination under the 

 Microscope ; premising, that so far as is known, the same method 

 will be equally successful with any of the web-spinning spiders. 



A fine Epeira Diadema, suspended as usual by his thread, 

 being available, six ordinary slips of microscopic glass were placed 

 in readiness to have the spider's thread wound upon them as it was 

 spun. The idea acted on was, that the threads issuing from the 

 hundreds of " spinning-tubes " on the various papillae or teats, 

 known as " spinnerets," 7nust travel for an appreciable distance ere 

 they coalesced in a more or less hardened but still glutinous con- 

 dition, to make up what we call in popular language " the spider's 

 thread," and that, therefore, these ultimate fibrils, though numbered 

 by hundreds, and of exquisite fineness, could assuredly be intercepted 

 at a point sufficiently near the spinnerets to cause the strands 

 to remain separate on the surface of the glass slip, instead of 

 coalescing. The slip was then made to catch the Epeira thread, 

 winding the line so as to come near the body of the spider, who not 

 liking the look of things, lowered himself, as was expected, rapidly 

 towards the ground to escape, and was as rapidly wound up, and 

 raised into mid-air. 



Now, as spiders do not like to part with spinning material if 

 they can avoid it, and as Epeira evidently got no nearer the ground, 

 he j)aused in his " paying out " of line to think a little, and he did 

 not cut his thread, inasmuch as a fall from that height was not to 

 be risked ; so, as he was now pretty steady, another slip was brought 

 into operation, the edge of it placed close under the spinnerets, or 

 in the actual position of the spider, rather above them, and once 

 having got adhesion of these issuing strands while they were quite 

 separate, it was manifest that with due precaution in winding up, 



