LETTERS ON ENTOMOLOGY. 151 
hesive or sticky, but the circles are. If ex- 
amined with a microscope, they will be found 
studded with little shining drops like dew, formed 
of a viscid gum, which catches the insects that 
alight upon it, like bird-lime. M. Q. D'Isjonval 
asserts, that the geometric spiders are always 
regulated by the future probable state of the 
atmosphere, and that if the weather is about to 
be variable, wet, and stormy, the main threads 
which support the net will certainly be short ; 
but if fine settled weather is commencing, they 
will as invariably be very long. A prisoner of 
war in France, I believe, amused himself with 
watching his spiders, and foretold many very 
important changes of the weather ; indeed, if I 
recollect right, his little barometers procured 
him his freedom at last. 
There are many others which do not trouble 
themselves with making webs, but catch their 
prey openly, or rather, I should say, in a less 
artificial manner. Aranea atrox lurks in holes ; 
Aranea calycina places herself at the bottom of 
the calix of a dead flower, and pounces on the 
unwary flies that come for honey ; Aranea arun- 
dinacea buries herself in the thick panicle of a 
reed. Among the hunters the immense Aranea 
avicularia, two inches long, is the principal ; it 
