460 



Marvels of the Universe 



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THE NEST OF THE TRAP-DOOR SPIDER. 



This photograph is taken looking down on the 

 Spider's nest, and shows the admirable way in which 

 the insect hides its living-place. 



Photo 6u] [ir. .?. Berridge, F.Z.S. 



THE NEST OF THE TRAP-DOOR SPiDER. 



This nest has been dug out of the ground, and 

 shows the long tube excavated by the Spider for her 

 eggs. The -ivhole tube is lined with silk. 



wards into the gill-chamber, and is divided up' 'by thin, 

 scroll-like plates of bone covered with a delicate skin, 

 o\-er which ramifies a network of blood-vessels for the 

 purpose of absorbing oxygen. 



The Climbing Perch is a freshwater fish found in 

 India, Burma and the !Malay countries, while other 

 -pecies arc found in Africa. 



Nearly related to the Climbing Perch is the 

 " Snake-head," which is found in the grassy swamps 

 of India, China and the Phihppine Islands. Like its 

 more famous relative, it is also able to live long out 

 of the water and is provided %\ith a similar apparatus 

 for breathing atmospheric air, save that the scrolls of 

 bone are wanting. Thus the breathing surface is 

 much less in extent than in the Climbing Perch, and 

 its sojourns on land can only be of comparatively 

 short duration. Nor does it possess the power of 

 locomotion on land, so that it would seem that 

 this provision is only for the purpose of tiding over a 

 temporary shortage of water or of breathing atmos- 

 pheric air when, owing to the dr3dng-up of the 

 stream, the water which remains is too foul to breathe 

 bv means of the gills. 



TRAP-DOOR SPIDERS 



BY R. I. POCOCK, F.R.S. 



Not without reason have the burrows of Trap-door 

 Spiders been called " triumphs of protective archi- 

 tecture." The essential feature distinguishing these 

 burrows from those of other spiders — indeed, from 

 those of aU other animals — is the presence of a 

 movable lid hinged to the edge of the aperture, so 

 that it can be opened and closed at will. Moreover, 

 the outer surface of the Ud is covered by the Spider 

 wdth particles of moss or other vegetation growing in 

 the vicinity of the burrow, so that, when closed, it 

 exactly matches its surroundings and becomes practi- 

 cally invisible. By thus concealing the burrow the 

 Spider secures the double purpose of hiding from his 

 enemies and surprising his prey. 



When on the watch for food he takes up a position 

 at the top of the burrow beneath the lid, which is raised 

 just sufficiently to allow the occupant vvithin to peep 

 through the narrow chink. Then woe betide any beetle 

 or fly that passes within striking distance. Like a flash 

 the Spider is upon it and drags it underground, the 

 whole performance being accomplished with such 

 marvellous speed and precision that it is all over in 



