PECULIAR INTERRELATIONS 133 



nests, or abandoning them by the wayside. But a few are laid 

 in the nests of other birds, by them to be hatched. The only 

 care they appear to take to secure any degree of safety for 

 their offspring is when they pick holes in some, at least, of the 

 eggs they find in the nests they visit for their nefarious pur- 

 poses. Should any of these eggs succeed in hatching, the young 

 Cow-bird quickly seals the fate at any rate of most of the 

 callow-young, by sitting on them until they are smothered, 

 when the dead bodies appear to be thrown out by the Cow- 

 birds' foster-parents. Even when these strange birds exhibit 

 sense enough to deposit their eggs in nests where incubation is 

 going on they not seldom exhibit a curious lack of discernment, 

 since several females will deposit their eggs in the same nest, 

 or they will stupidly stab and break their own egg while destroy- 

 ing those of their dupes ! The only respectable member of the 

 family, Molobrus badius, is victimised by its near ally M. 

 rufoaxiilaris, though strangely enough another species, M. 

 bonariensiSy which is found in this same region — Buenos Ayres — 

 is always detected and repulsed when it similarly attempts to 

 rid itself of the ties of parentage. 



While among the Cuckoos the majority appear to be para- 

 sitic some at least retain their normal parental instincts, 

 while in others, aberration has taken another course, which, 

 in some ways, recalls features which obtain among the Cow- 

 birds. Thus certain New World Cuckoos, known as the White 

 Ani {Guira) and the Black Ani {Crotophagd), the former repre- 

 sented by only a single species {Guira piririqua), the latter by 

 at least three species {Crotopkaga ani, C. major and C. sulci- 

 rostris), exhibit a most remarkable prolificness in the number of 

 eggs produced, as many apparently, or more, being dropped about 

 promiscuously as are deposited in nests. But these Cuckoos are 

 not parasitic. Instead they perform their maternal duties on 

 the co-operative system. A number of females combine to build 

 a large nest of twigs which is placed in a tree, and lined with 

 moss and green leaves. Herein each deposits about five eggs, 

 to the number of twenty or more, and upon these, according to 

 some accounts, all proceed to sit, huddled together, until the eggs 

 are hatched, when the company of mothers proceed to the work 

 of feeding. So flimsily are these nests constructed, however, that 

 not seldom the eggs fall through the nest as they are laid, while 



