8200 



Arachnida. 



Lecture on Spiders.— At the Brighton Royal Literary and Scientific Institution, 

 on Tuesday evening, the 6th of October, Mr. J. Robertson read a paper on spiders, 

 which he said was not a compilation, but the result of original observations and experi- 

 ments. Those whose habits he had watched were of five kinds: — 1. Tunnel spiders, 

 which formed tunnels several feet deep in the earth, lined throughout with silk, and 

 closed at the entrance with a door on hinges, which the spider could hold fast on the 

 inside against the attacks of small birds or other enemies. That the creature might 

 not perish when thus shut up for want of air, all round the doorway were small 

 veutilating tubes. It was a native of the West Indies, the Ionian Islands and 

 Australia. The fangs of this creature worked horizontally, and it had six eyes, 

 arranged horse-shoe fashion, with the opening in front. Seven years ago a specimen 

 had been found near Hastings, confirming an old tradition that they did exist in 

 England; and he had himself recently found one near Brighton. The tube of this 

 creature, found in a lump of clay, was produced, as also another specimen (the upper 

 part, including the trap-door) from Australia. 2. Spiders, tiny red creatures, which 

 skate on the surface of the water. This, he believed, they accomplished by entangling 

 in the brushes at the end of their feet warm, and, consequently, light globules of water, 

 and with these as runners skimmed over the colder and denser water forming the strata 

 helow. 3. The diving spider, which makes a small cell, in the shape of an egg, beneath 

 the water, and attached to the stem of some plant, but not of spun silk, the wall being 

 formed of a secretion from the mouth. This creature collects globules of oxygen gas by 

 the electrical attraction of the hairs of its body, and conveys them into its egg-shaped 

 house, thus obtaining a supply of vital air beneath the water. Some spiders enclose 

 their cast-off skins in a silken bag, possibly to stop the escape of noxious vapours. 



4. Certain spiders can fly: they dart out threads from their spinners in a horizontal 

 direction to a considerable distance. He saw one put out a thread six inches long, 

 and, turning slowly round, "box the compass." Lister witnessed the same fact two 

 hundred years, and Latreille thirty years ago, though Blackwall denies that spiders 

 have the power. There are spiders which send out their threads as floats, and are 

 carried by them through the air. Frequently little cobwebs float over the fields, and 

 if, when they descend to the earth, they be examined, are found each to contain a 

 little red spider. In 1822 the yeomanry at Kidderminster fired a salute in honour of 

 George the Fourth's coronation, when down came a shower of these little red spiders. 



5. Labyrinth spiders form a web in shape like a wide-mouthed funnel. Three of these 

 creatures he placed in a box, with a glazed aperture at the top, so that he might ob- 

 serve their habits. Each spun a labyrinth near the opening, where the food was 

 introduced. A blue-bottle rly they easily killed by leaping on his back and plunging 

 the mandibles into his thorax. A beetle gave them more trouble, but they spun 

 threads across his path as he walked about, and when his legs on one side became 

 entangled in these threads, they tilted him over and so despatched him. They killed a 

 moth by leaping on his back, but carefully avoided the strokes of his quickly vibrating 

 wings, and a grasshopper by first clinging to one of his legs. Lastly, Mr. Robertson 

 mentioned that he discovered between thirty and forty spiders working together, 

 co-operatively, to form a large web covering a lump of clay, which he produced, with 

 the web upon it. Some acted as overseers, others as woofers and others as warpers. 

 Some conversation followed, and Mr. Robertson concluded by observing that studying 

 the habits of spiders might even lead to important results, for if we learned how these 



