170 



BRANCH VERTEBRATA. 





Nest of Sociable Weaver-bird 



FIG. 290. 



a long tube for the entrance, made of fibers so loosely 



put together that a reptile 

 would drop off into the 

 water. Others similarly sus- 

 pended are pyramidal in 

 shape and divided into two 

 chambers the outer, per- 

 haps, for the use of the 

 male, and the inner for the 

 eggs of the female. 



The Sociable Weaver- 

 bird is polygamous. A col- 

 ony of two or three hun- 

 dred construct in a tree a 

 huge, sloping roof, imper- 

 vious to rain. Beneath this, 

 side by side, each female 

 makes her nest, three or 

 four inches in diameter, 

 weaving it to the roof. 

 ^^ completed, the lower 



surface of the umbrella-like structure appears perforated 



by small openings, like the cells of a bee-hive, all the 



birds living together in 



perfect harmony. 



The Cow-bird is gre- 



garious and polygamous, 



exhibiting neither conju- 



gal nor parental affection. 



The female lays in the 



nests of other birds, usu- 



ally those of similar ap- 



\.) 



FIG. 291. 





petite, and whose eggs hatch two days later. The adoptee 



