240 THE HARMONIES OF NATURE. 



pounces upon it and seals its doom. Even wasps, which other 

 spiders are averse from attacking, either on account of their 

 sting or of the hardness of their integuments, are fearlessly 

 encountered and defeated by this formidable spider ; for its 

 breast and feet are very hard, and the abdomen is covered with 

 a thick skin, so that it does not fear their sting, and its strong 

 and hard mandibles are able to crush their horny coverings. 

 So beautifully is the organization of the spiders modified, ac- 

 cording to the various prey which has been destined for their use ! 



The Salticus scenicus, a common black-and-white spider, 

 which may always be seen in summer upon walls and windows, 

 disdains the use of any snare, and, like the tiger, relies upon his 

 spring alone for the overpowering of his prey. When he spies a 

 fly at a distance, he approaches softly step by step, and seems to 

 measure his distance from it by the eye; then if he judges that 

 it is within reach, first fixing a thread to the spot on which he 

 is stationed by means of his forefeet, which are much larger 

 and longer than the others, he darts on his victim with such 

 rapidity and so true an aim, that he seldom misses it. He is 

 prevented from falling by the thread j list mentioned, which acts 

 as a kind of anchor, and enables him to recover his station. 



The subterranean labours of the large trapdoor spiders, of 

 which many species abound in the warmer climates, are no less 

 admirable than the nets of the weaving arachnidse. These 

 hideous brown or black-haired creatures, which sometimes 

 attain a length of three inches, while their legs embrace a circle 

 of half a foot in diameter, dig deep tubular holes in the earth, 

 from which they sally forth after sunset in quest of prey, 

 or to which they retreat in case of danger. The interior of the 

 nest, which is sometimes nine inches deep, is lined with a double 

 coat of tapestry the one nearest the wall, which is of a coarser 

 tissue, being covered with a pure white silken substance like 

 paper b u t it is chiefly in the construction of the trapdoor 

 which secures its entrance that the little architect displays a 

 remarkable ingenuity. This lid is a flap of the same substance 

 as the tube, of a circular shape, so as to fit the orifice with 

 perfect accuracy ; and attached to the tube by a tolerably wide 

 hinge, so that on closing it does not fall to either side, but 

 comes true and fair upon the opening which it guards. A cu- 

 rious instinct teaches the spider to make her tunnel in some 



