138 ARACHNIDA. 



threads in the air, at one end of which a minute spider is 

 found to be attached. The mode in which this is effected 

 has been the subject of considerable discussion. Some 

 authors contend that the spider has the power of directing 

 these threads at pleasure towards a determined object. 

 Others maintain that the thread is discharged independently 

 of any influence from the atmosphere ; others again, that it 

 is entirely electrical ; but the most generally received opinion 

 is, that the spider, directing its spinnerets in the direction of 

 a current of air, discharges a thread which, being exceedingly 

 light, is carried on by the air to such a length as to be able, 

 from its buoyancy, to support the slight weight of the spider 

 itself. In France, the floating threads which support the 

 small spiders are called jils de la Vierge, and it has been 

 supposed that they were exclusively formed by a spider 

 which has been named Aranea obstetrix; but this is not 

 correct, neither is the species here noticed any thing else 

 than a young and imperfectly described individual belonging 

 to the genus Epeira. 



Nearly all the different species of spiders envelope their 

 eggs in a covering of silk. The mass of eggs, thus protected, 

 of the Epeira diadema, may be constantly observed during 

 the winter months in the angles of walls of rooms exposed 

 to gardens, frequented by the perfect insects, which, after 

 impregnation, make their way into the houses for safety. 

 These cocoons, as they may be called, differ in the different 

 species. In some they are globular, in others oval, and in 

 some depressed. The care with which these cocoons are 

 guarded by some species is quite astonishing. Some of the 

 species carry them about with them beneath the abdomen, 

 and it is a matter of the greatest difficulty to compel the 

 mother to quit her charge, and even then she wanders about 

 the spot searching for it with the greatest solicitude. The 

 egg cocoon of the very handsome species Epeira zebra, as 



