CHAP. I. INSTINCT OF PARASITIC BIRDS. 19 



wings, as a buckler, struck her enemy with the horny 

 protuberances upon the other, which, like little clubs, 

 served the more effectually to knock him down as he 

 raised himself to the blow : at last he staggered and 

 fell : the conqueror then despatched him, and with one 

 stroke of her bill laid open his skull."* 



(22.) The instinct of the nestling cuckoo is not 

 more remarkable than that of the parent. The Euro- 

 pean species (fig. 4.), as is 

 well observed by White of 

 Selborne, does not lay its 

 eggs in other birds' nests in- 

 discriminately, but, by a won- 

 derful instinct, selects only 

 those of soft-billed insecti^- 

 vorous birds, such as the 

 wagtails, hedge-sparrow, tit- 

 lark, whitethroat, and red- 

 breast, to whom it can 

 intrust the proper feeding of 

 its progeny. The North 

 American cuckoos, however, 

 being of a different species, more frequently lay their 

 eggs in the nests of the cowpen birds (Molothrus pe~ 

 coris Sw.), whose bills, from being larger and thicker 

 than those of a sparrow, might lead to the belief that 

 they fed their young upon that grain which the old 

 birds are known to be fond of. It seems, however, 

 that although this species, in their adult state, are grani- 

 vorous, yet that they are also insectivorous, and feed 

 their young with this latter aliment rather than with 

 the former. Hence it is that the young cuckoo is 

 still nourished with insects until it can fly, when it 

 quits the nest and shifts for itself. 



(23.) QUADRUPEDS claim our next attention. It is 

 in this class, more than in any other, we find that kind 

 of superior instinct formerly alluded to, which makes 

 them not only the companion, but the friend, of man. 



* Le Vaillant's Second Travels, voL ii. p. 247. \ 



c 2 



