INTRODUCTION. D 



nor the mason-bee, as she plasters together her 

 neat mud-wall cottage or cell, as the future habi- 

 tation of her young ; but there are few persons 

 unacquainted with the masonry of the chimney 

 swallow, or of the house-martin twittering on the 

 eaves. With no other tools than those which 

 nature supplies, how cleverly do these creatures 

 shape and mould their nests into the required 

 form, using for their work a mortar carefully pre- 

 pared by their own labour and skill, and just of 

 the consistency required. Few, again, may have 

 had an opportunity of seeing carpenter-bees boring 

 holes in posts or palings, and forming their smoothly 

 chiselled cells, or of inspecting the partitioned 

 galleries dug out in old timber by carpenter- wasps ; 

 but perhaps many persons have observed the 

 colonies of emmets, or carpenter-ants, working in 

 the trunks of decaying oak or willow trees ; or 

 they may have listened to that interesting carpen- 

 ter-bird, the wood-pecker, tapping and boring into 

 trees, in pursuit of insects, and for the purpose of 

 making a nesting-place for its young. Most of us 

 know only by hearsay that there are tailor-birds, 

 common enough in American orchards, who sew 



