96 Dr. Jenner on the Migration of Birds. 



food for its present support. Now it is very obvious that this 

 bird, and its companions, must have taken a long flight, and 

 probably in a very short space of time; for the intense frost, 

 that was of such duration and so severely felt here, extended 

 far into the more southern parts of Europe, beyond which 

 they must have resorted for that plenty of food which gave 

 plumpness to the one I examined, and doubtless to the whole 

 flock, from their appearing so wild and vigorous. It clearly 

 appears, that in their flight they exceeded the progress of the 

 thaw, as the northern birds did that of the frost. This thaw, 

 though it was again succeeded by frost, came on very rapidly, 

 and occasioned, by the sudden melting of the snow, those de- 

 structive inundations through the kingdom, that will not readily 

 be forgotten. 



This account of the fieldfare sets the fact of migration, 

 though from an accidental cause, beyond the reach of doubt. 

 There was no support for it here ; the ground was deeply co- 

 vered with snow, and the intense frost, by its long duration, 

 had destroyed every thing that could afford it succour; it 

 must therefore have taken a long flight from this country, 

 and returned to it again at the approach of temperate 

 weather. 



Having already made so many digressions, I cannot add 

 another without offering an npology ; but as there is some- 

 thing so like providential design in the order in which the 

 song birds chaunt out their warblings during a losg summer's 

 day, I trust the Society will pardon my laying before them 

 the following observations on the subject. 



We must observe, that nature never gives one property 

 only to the same individual substance. Through every gra- 

 dation from the clod we tread upon to the glorious sun which 

 animates tthe whole terrestrial system, we may find a vast 

 variety of purposes for which the same body was created. If 

 we look on the simplest vegetable, or the reptile it supports, 

 how various yet how important in the economy of nature 

 are the offices they are intended to perform ! The bird, I 

 have said, is directed to this island at a certain season of the 

 year to produce and rear its young. This appears to be the 

 grand intention which nature has in view ; but in consequence 

 of the observation just made, its presence here may answer 

 many secondary purposes ; among these I shall notice the 

 following. The beneficent author of nature seems to spare 

 no pains in cheering the heart of man with every thing that 

 is delightful in the summer season. We may be indulged 

 with the company of these visitors, perhaps, to heighten, by 

 the novelty of their appearance, and pleasing variety of their 



notes, 



