The Cotton-bees 



dcm Anthidium belongs to another schooL 

 With her droppings she fashions masterpieces 

 of marquetry and mosaic, which wholly con- 

 ceal their base origin from the onlooker. Let 

 us watch her labours through the windows of 

 my tubes. 



When the portion of food is nearly half 

 consumed, there begins and goes on to the 

 end a frequent defecation of yellowish drop- 

 pings, each hardly the size of a pin's head. 

 As these are ejected, the grub pushes them 

 back to the circumference of the cell with 

 a movement of its hinder-part and keeps them 

 there by means of a few threads of silk. The 

 work of the spinnerets, therefore, which is 

 deferred in the others until the provisions are 

 finished, starts earlier here and alternates with 

 the feeding. In this way, the excretions are 

 kept at a distance, away from the honey and 

 without any danger of getting mixed with it. 

 They end by becoming so numerous as to 

 form an almost continuous screen around the 

 larva. Ihis cxcrcmcntal awning, made half 

 of silk and half of droppings, is the rough 

 draft of the cocoon, or rather a sort of scaf- 

 foKlIng on which the stones are deposited un- 

 til they are definitely placed in position. 



289 



