CHAPTER IX. 



THE AERONAUTIC OR BALLOONING HABIT. 



Many accounts have been published, more or less valuable, of what 

 are popularly known as "flying spiders." As the natural habits of familiar 

 animals liave come to be better understood, this popular phrase 

 "Plymg^ has yielded to the more accurate one, "ballooning spiders." How- 

 Spi ers. ^^^^^_ called, the habit referred to has been and remains interest- 

 ing and attractive to the ordinary scientific observer. The fact that an 

 animal which has none 9f the natural provisions for progress through 

 the air granted to winged creatures, should, nevertheless, be able to over- 

 come gravity, mount into the atmosphere, and accomplish aerial jour- 

 neys, sometimes of immense distances, is certainly well . suited to capti- 

 vate the imagination, awaken curiosity, and stimulate research. This 

 interest is quickened by the fact that the mode by which the spider 

 aeronaut reaches these results bears a marked likeness to the artificial 

 means by which man has himself solved the problem of aerial naviga- 

 tion. The thought that the invention of Mongolfier's mind possesses this 

 striking analogue in the natural history of an inferior creature, strikes 

 into a profounder depth than curious wonderment, and touches the prob- 

 lem of a Supreme Mind over Nature. 



I. 



I have studied the aeronautic habit of spiders from representatives of 

 the Orbweavers, Tubeweavers, Citigrades, Laterigrades, and Saltigradcs, 

 and have not been able to note any difference in the mode of flight as 

 practiced by all. It is probable that the young of most spiders, and many 

 of the small species of all the great groups, are more or loss addicted to 

 such mode of motion. Certainly the habit is very strongly fixed in Orb- 

 weavers. Epeiroid spiderlings just out of the cocoon lift themselves into 

 the air and sail away, precisely in the manner hereafter described. In- 

 deed, the infant aranead, when separated from its fellows and exposed 

 to a strong puff of air, seems instinctively to throw out its spinnerets and 

 send forth jets of silken filament, just as a human baby sets in motion 

 its feet and hands. 



As the jets almost instantly acquire sufficient buoyancy to counter- 

 balance the spider's weight, the creature becomes an aeronaut, nolens 

 volens, and one can see how readily the deliberate habit of ballooning 



(25G) 



