The Natural History of Selborne

21 house-martins appeared playing about under the hanger.  The air was full of insects.  Others that saw the martins in an other part of the hanger say there were more than 150!  This was a mistake.  Note: no martins have been observed since Oct. 7th ’til this day, when more than 20 were playing about & catching their food over my fields, & along the side of the hanger.  It is remarkable that tho’ this species of Hirundines usually withdraws pretty early in Oct. yet a flight has for many years been seen again for one day on or about the 4th of Novr.  Father it is worthy of notice, that when the Thermr rises above 50, the bat awakens, & comes forth to feed of an evening in every winter-month.  These circumstances favour the notion of a torpid state in birds; & are against the migration of swallows in this kingdom.