NOTES FROM GRAVESEND. 179 



experience the young are very, ravenous, that possibly one young one 

 requires as much food as the parents could procure ; they therefore 

 provide a nurse for each, and hence the reason for the young cuckoo 

 turning out all its companions, for it appears that this one charge is 

 sufficient to occupy the whole care of its foster parents ; and allowing 

 this reasoning to be just, it will also account for the cuckoo's not sitting 

 upon even one egg ; for how could she build her nest, and hatch one 

 egg, and at the same time provide for the hatching of the others ? 



NOTES FROM GRAVESEND. 



BY ORNITHOLOGUS. 



THE hybernaculum, or winter retreat of the swallow tribe, presents 

 a question which naturalists, from Linnaeus downwards, have been 

 unable to solve. It appears to me that this arises in a great measure 

 from the want of corresponding societies in different parts of the world, 

 which would communicate to each other the exact periods of their de- 

 parture and return, and thus eventually elicit the truth. This remark 

 is founded on the assumption that they do actually migrate ; but it will 

 be, at the same time, advantageous to pay attention to all those circum- 

 stances connected with this remarkable genus that may transpire in 

 our own country, as a careful collation of such facts, nantes in gurgite 

 vasto, will contribute essentially to determine a point at once so 

 mysterious and so interesting. Under this impression, I mention a 

 circumstance which fell under my own observation, and which seems to 

 favour the idea of their remaining torpid during the winter months. 

 During the severe winter of 1830-31, a labourer, while threshing in a 

 barn, had his attention drawn to a swallow which flew from one bay (as 

 it is called) to the other. It flew so low that it almost touched him, 

 and so feebly that he not only had sufficient time to determine its 

 species, but nearly succeeded in knocking it down with his flail. It, 

 however, managed to reach the top of the corn on the opposite side, and 

 did not again appear. Here we have a strong instance, as I before 

 observed, in favour of their torpidity, as, even admitting this to have 

 been a young bird hatched late in the summer, it must have existed for 

 some months in a state of inactivity, from which it only emerged for a 

 short time when disturbed by some accidental circumstance. I have 



