The Life of Spiders 



single easily recognized species that is believed by some people 

 to be dangerous. Surely one should not hesitate to study spiders 

 on account of their venomous nature. 



XII.— THE AERONAUTIC SPIDERS 



Although spiders like man possess only legs as organs of 

 locomotion, like man they are able to travel through the 

 air by artificial means. Long before the invention of balloons 

 or of aeroplanes, spiders had solved the problem of aerial 

 navigation. 



The method adopted by spiders differs greatly from any of 

 those adopted by man in his efforts to navigate the air. The 

 spider's method is more closely analogous to that by which many 

 seeds, as those of the dandelion, are carried long distances; and 

 the object is the same, the distribution of the species. 



Attached to the dandelion seed there is a pappus consisting 

 of a bundle of fine threads. These, when the seed is mature and 

 fitted to start upon its journey, spread apart forming a very light, 

 nearly spherical mass, which is easily carried away with the at- 

 tached seed by the wind. Thus the seeds of a single plant are 

 scattered over a wide area instead of too thickly seeding the place 

 of their origin. 



With spiders it is not the seeds or eggs that are distributed 

 but the spiders themselves; and the object by which they are 

 buoyed up when carried by the wind differs from the pappus of 

 a seed in consisting largely of a single thread, or a bundle of 

 parallel threads. 



It is usually, but not invariably, very young spiders that 

 exhibit the aeronautic habit; and exhibitions of it are most often 

 observed in warm and comparatively still autumn days. At 

 this time great numbers of young spiders, of many different 

 species, climb each to the top of some object. This may be a 

 fence post, the top of a twig, the upper part of some herb, or 

 merely the summit of a clod of earth. Here the spider lifts up 

 its abdomen and spins out a thread, which if there is a mild 

 upward current of air is carried away by it. Occasionally the 

 spider will attach a small flocculent mass to this thread which 

 will increase the force of the current of air upon it. This spinning 

 process is continued until the friction of the air upon the silk is 



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