THEIR REPRODUCTION (NESTS) 263 



leads into a second chamber, where the nest is 

 completed with a bed of soft dry grass. The 

 whole concern measures about a foot in dia- 

 meter, and may weigh as much as ten pounds. 

 As pointed out by Mr. Hudson, who has had 

 exceptional facilities for studying many species 

 of Wood Hewers, some other species excavate in 

 the earth, making long cylindrical burrows four 

 or five feet in length, terminating in a round 

 nest chamber; others that are of arboreal habits 

 nest in holes in wood. The marsh-frequenting 

 species attach spherical or oval domed nests to 

 the reeds, in some cases woven grass and clay 

 being so cleverly combined that the structure is 

 impervious to wet, practically indestructible, and 

 light as a basket. Another type is a large struc- 

 ture made of sticks, placed in bushes and trees, 

 to make and keep in repair which the owners 

 work more or less constantly all the year round. 

 These stick nests vary greatly in size and shape. 

 Some have a spiral passage leading from the 

 entrance to the cavity where the eggs are de- 

 posited, this being in many cases only just big 

 enough to hold the owner. In another species, 

 however (Homorus gutturalis), this nest cavity is 

 so large that " if the upper half of the nest or 

 dome were removed, a Condor could comfortably 



