TEGENERIA MEDICINALIS. 



doubles and trebles the thread that borders its web, by open- 

 ing all its papilla at once ; and so secures the edges as to 

 prevent the wind from displacing the work. The edges being 

 thus fortified, the retreat is next to be attended to, and this is 

 formed like a funnel, where the little workman lies concealed. 

 To this there are two passages or outlets, one above and the 

 other below, very artfully contrived, to allow the animal an 

 opportunity of making excursions at proper seasons, of ex- 

 amining every corner, and clearing those parts which become 

 foul or encumbered. It often happens, also, that from the 

 main web there are several webs extended at. some distance 

 on each side ; these may be considered as outworks of the 

 fortification, which, whenever touched from without, the spi- 

 der prepares for attack or self-defence. If the insect infring- 

 ing happens to be a fly, it springs forward with great 'agility ; 

 but if, on the contrary, some enemy stronger than itself, it 

 then keeps within its fortress, and never ventures out till the 

 danger is past. The spider also exhibits an instinct of a very 

 uncommon nature. When put in terror by a touch of the 

 finger, the spider runs off with great swiftness ; but if he 

 finds that, whatever direction he takes, he is opposed by an- 

 other finger, he then seems to despair of being able to escape, 

 contracts his limbs and body, lies perfectly motionless, and 

 counterfeits every symptom of death. In this situation spi- 

 ders have been pierced with pins, and torn to pieces without 

 their discovering the smallest mark of pain. The simulation 

 of death has been ascribed to a strong convulsion or stupor, 

 occasioned by terror. But this solution of the phenomenon 

 is erroneous and not satisfactory, The experiment has re- 

 peatedly been tried, and it is uniformly found, that, if the 

 object of terror be removed, in a few seconds the animal 

 runs off with great rapidity. Some beetles, when counter- 

 feiting death, suffer themselves to be gradually roasted with- 

 out moving a single joint. 



The garden spider, Epeira diadema, appears to work in a 

 different manner from that of the above. It spins a large 

 quantity of thread, which, floating in the air in various di- 

 rections, happens, from its glutinous quality, at last to adhere 

 to some object near it, a lofty plant or the branch of a tree. 

 The spider is anxious to have one end of the line fixed, that 

 it may be enabled to secure and tighten the other ; it accord- 

 ingly draws the line when thus fixed, and then, by passing 



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