38 INSECT LIFE IN POND AND STREAM 



some floating weed. Then she begins to spin 

 a fine silken thread with a little spinning 

 machine, called a spinneret, which she has at 

 the end of her body, just as a spider has. With 

 this silk Mother Beetle gradually weaves her 

 little cocoon, carefully pressing and shaping 

 it with her fore-legs as it grows. 



She works away steadily for some time, but 

 at last the tiny silken bag is finished, and in 

 it she places about fifty or sixty little pointed 

 eggs. When this is done Mother Beetle care- 

 fully closes the mouth of the bag, weaving the 

 ends firmly together with silk, for it is most 

 important that the precious eggs shall not get 

 wet, and the cocoon is so strongly and beauti- 

 fully made that no water can get inside. It 

 is filled, too, with air, and floats on the top of 

 the water like a little boat. 



But Mother Beetle has not quite finished her 

 work yet : as a finishing touch she adds a tiny 

 mast or funnel to the little boat, which stands 

 upright at one end. Some beetles anchor their 

 cocoons to the water- weeds with a silken rope, 

 but others let them float away and drift here 

 and there on the top of the water. 



The tiny boat floats on the water for two or 

 three weeks ; it is so well balanced that it never 



