274 EIltUNDINIDJE. 



young do not occasionally stay behind, and hibernate in 

 hollow trees, holes of rocks, and the banks of pools and 

 rivers. Mr. Bell considers the question as settled in the 

 affirmative, namely, that they do all migrate; and such, 

 no doubt, is the rule ; but with all respect for so high an 

 authority, I am inclined to the opinion that individuals 

 occasionally remain, perhaps in consequence of having 

 been disabled by accident at the season when the migratory 

 instinct was in its active force, or from some other cause 

 unknown to us. Such stragglers would, if the succeeding 

 winter proved severe, perish of hunger (that they become 

 torpid I cannot suppose), but if it turned out to be mild 

 they might survive till the following spring. This sup- 

 position will account for the appearance of Swallows late 

 on in winter; several instances of which have been recorded 

 by authors who, whether accurate observers or not, certainly 

 believed that they were reporting truly. That they were 

 seen only on warm days is of course no evidence that they 

 had been roused from a state of torpor by the unusual 

 warmth. Sunny days in winter tempt people to walk 

 abroad and to resort to the same places which winter-gnats 

 would choose for their gambols. Here, too, the stray Swallow 

 would be found ; but in dark stormy weather the gnats 

 and the Swallow would stay at home, and the ornithologist 

 would have little temptation to do otherwise. I happen 

 to be myself among the number of those who on personal 

 evidence believe that individual Swallows do remain in 

 England long after the period of general migration. I 

 was walking through a limestone quarry at Saltram on the 

 bank of the Plym, in Devonshire, many years ago, on the 

 24th December, when I saw a Swallow, whether a Chimney 

 Swallow or Martin, I cannot positively affirm, wheeling 

 about, and evidently hawking for gnats near the face of 

 the cliff. The season was a mild one, the air still, and 

 the sun shining brightly against the limestone rocks, from 

 which much heat was reflected. That the bird had been 



