162 THE BIRDS OF SHERWOOD FOREST. 
yet it has a very pleasing and melodious warble; it 
chiefly indulges in this early in the morning, even 
long before sunrise, or towards evening, and it is quite 
in keeping with the gentle character of the bird. 
By what extraordinary instinct do the swallow and 
its congeners ascertain what weather is prevailing in 
this country, for such really seems to be the case? In 
some years, when the season has been backward, I have 
remarked a few pairs only arrive, and even these have 
seemed after a day or two to disappear. In the year 
1849 the spring was particularly backward ; April was 
cold and bleak, and unfavourable to the development 
of insect life ; and not until the 11th of May did any of the 
hirundines make their appearance, on which day I first 
noted a few pairs of the common swallow and the 
house martin, but the main body did not arrive until 
three days afterwards. This was no local occurrence, 
for the same ungenial weather was general throughout 
England. In 1847 I noticed the same phenomenon, 
under precisely similar circumstances as regards the 
weather. A few pairs arrived on the 29th of April, but 
immediately departed, and I saw no more until the 4th 
of May, when I remarked a single pair of swallows ; but 
these were not joined by the main body until the 6th. 
By what mysterious system of telegraphy was the 
intelligence conveyed to the southern voyagers that their 
journey had better be delayed fora time? We boast of 
our wisdom and intelligence, but how little able are we 
to elucidate facts like these. 
During the time of building I have often seen the 
swallows frequent the gutters, or any wet place in the 
village street, from whence they obtain the mud for 
their nests; their feet, however, and short legs do not 
