66 Proceedings of Philosophical Societies. [Jan. 



in the other insects which have been examined ; it is also large 

 in the moth and in the caterpillar. 



The reading was commenced, likewise, of Some Observations 

 on the Migration of Birds; by the late Dr. Edward Jenner, 

 F. R. S. ; communicated by his Nephew, Mr. H. C. Jenner. 



Nov. 27. — Dr. D. Cresswell and Prof. Barlow were admitted 

 Fellows of the Society ; and the reading of Dr. Jenner's paper 

 was concluded. 



Dr. Jenner had intended to present this paper to the Royal 

 Society himself, but was prevented from fully completing it, as 

 to arrangement, by his extensive correspondence on the subject 

 of vaccination. It commences with some general observations 

 on the Migration of Birds, and particularly with respect to their 

 capability of taking such great flights as migration must require, 

 and which some writers have questioned. Dr. Jenner brings 

 forward various facts, to show that there are no grounds for 

 such doubt ; among which are the following : a hobby-hawk 

 was seen in a vessel near Newfoundland ; and an owi, seemingly 

 the common brown owl, flying above the Atlantic wave, with as 

 much agility as if pursuing a mouse in the fields ; cuckoos, 

 snipes, and other birds, have likewise been seen in the Atlantic ; 

 a flock of birds resembling linnets settled on the rigging of a ship, 

 remained awhile chirrupping in concert, and then flew away ; 

 geese have been caught in Newfoundland with their crops full 

 of maize, a species of corn which is not grown but at an im- 

 mense distance from that island. The discussion of this branch 

 of the subject is succeeded by some remarks on the faculties of 

 discrimination and guidance which must be exercised by birds, 

 in the long flights thus taken, and which, Dr. J. conceives, must 

 be of some peculiar and unknown nature ; pigeons, it is ob- 

 served, which have been taken several hundred miles, completely 

 secluded from the light, by being shut up in a box, will, when 

 set at liberty, immediately return to the place whence they were 

 taken. The periodical disappearance and return of birds has 

 been ascribed to hybernation, but of this Dr. Jenner never wit- 

 nessed an instance ; nor could he ever obtain any satisfactory 

 evidence of it. When birds appear for the season, they are 

 never in the emaciated and weakened state attended with, loss 

 of fat, seen in hybernating quadrupeds when they quit their 

 retreats ; but, on the contrary, they are quite vigorous, and as 

 active as at any period. With regard to the supposed immersion 

 of birds in ponds and rivers for the winter, Dr. J. remarks, that 

 their respiratory organs are very similar in structure to those of 

 quadrupeds, and are no better adapted for performing their 

 functions under water. He took a swift, about the 10th of 

 August, or on the eve of its departure, and held it under water, 

 when it died in two minutes. It has been conjectured, that 

 repeated alternate immersions and emersions might have the 

 effect of altering the corresponding action of the heart and 



