246 ABOUT SPIDERS AKD THEIE WEBS. 



earth, and cause undulating waves of warm air to ascend 

 continually from it. The floating thread comes across 

 one of these air waves, and when the spider feels itself 



MOKEY-SPIXXERS. 



pulled upwards, it loosens its hold of the plant and soars 

 aloft, upborne on the air. 



Thousands upon thousands of little spiders thus take 

 their aerial excursions, and when their parachute-threads 

 become interlaced, they form large, loose, irregular sheets 

 of silken Aveb. Sometimes the air is filled with these 



