120 ON THE INSTINCTS OF BIRDS. 
of Jonston* that the Nightingales which visit Scotland 
have not the same harmony as those of Italy, Dr. 
Darwin was hastily led to conclude that the songs of 
birds in general are artificial. Having observed also 
that poultry readily obey their usual summons to be 
fed, and that young Ducks hatched under the Domestic 
Hen soon appear to understand her calls, and giving 
credit to the mistaken idea that Wagtails and Hedge- 
Warblers feed the young Cuckoos they bring up long 
after they leave the nest whenever they hear their 
cuckooing (which, on the authority of Linnzus f, he 
states to be their cry of hunger), he was induced to 
adopt the same opinion respecting their calls. Now, 
whether the song of the Nightingale results from 
education, as Kircher maintains, or whether it is 
wholly independent of tuition, I have never had any 
direct means of deciding, as the bird is only an acci- 
dental visitor in this part of the kingdom. From 
unexceptionable experiments, however, made with the 
greatest care on several other species of British Sing- 
ing Birds, I have no hesitation in affirming that the 
peculiar song of each is the natural consequence of an 
instinctive impulse, combined with a suitable state of 
the vocal organs. This latter condition deserves par- 
ticular attention ; for it is a fact, which has been very 
generally overlooked, that most of our songsters are 
absolutely unable to continue their melodious strains 
* Pennant's - British Zoology. 
+ + Systema Nature.’ 
