THE EDUCATION OF YOUNG BIRDS 247 



own kind. Here again, then, actual experiment is 

 necessary to determine which view is correct. Such 

 experiments were performed by Mr. John Blackwall 

 as long ago as 1823. He writes : — 



" I placed the eggs of a redbreast in the nest of a 

 chaffinch, and removed the eggs of the chaffinch to that 

 of the redbreast, conceiving that, if I was fortunate in 

 rearing the young, I should, by this exchange, ensure 

 an unexceptional experiment, the result of which 

 must be deemed perfectly conclusive by all parties. 

 In process of time these eggs were hatched, and I had 

 the satisfaction to find that the young birds had their 

 appropriate chirps. 



" When ten days old they were taken from their nests, 

 and were brought up by hand, immediately under my 

 own inspection, especial care being taken to remove 

 them to a distance from whatever was likely to influence 

 their notes. At this period an unfortunate circum- 

 stance, which it is needless to relate, destroyed all 

 these birds except two (a fine cock redbreast and a hen 

 chaffinch), which, at the expiration of twenty-one 

 days from the time they were hatched, commenced the 

 calls peculiar to their species. This was an important 

 point gained, as it evidently proved that the calls of 

 birds, at least, are instinctive, and that, at this early 

 age, ten days are not sufficient to enable nestlings 

 to acquire even the calls of those under which they 

 are bred. . . . Shortly after, the redbreast began to 

 record (i.e. to attempt to sing), but in so low a tone 

 that it was scarcely possible to trace the rudiments 

 of its future song in those early attempts. As it 



