262 [ Sept. 1847. 



Mr. Townsend exhibited a living specimen of the common 

 mouse, ( Mus musculus) which possessed the remarkable pecu- 

 liarity of uttering notes resembling those of a singing bird. 

 The notes were uttered in very rapid succession, and although 

 weak, could be readily [distinguished at the distance of several 

 yards. The animal was recently taken in an ordinary trap, by 

 a lady residing in the Northern Liberties. 



Dr. Warrington, of England, exhibited and explained the 

 modus operandi of an instrument of his own invention, which he 

 called Spirometer, the object of which he stated to be, to test the 

 capacity of the lungs in health and disease. " The amount of 

 cubic inches of air the lungs are capable of expelling, being 

 always in proportion to the height of the individual, and a scale 

 attached to the instrument indicating with accuracy any dimin- 

 ished capacity, a standard of health and disease could be thus 

 readily fixed, and the disorganization or contraction of the organ 

 early detected. " 



Meeting for Business, Sept. 28, 1847. 



Mr. Phillips in the Chair. 



The Committee to whom was referred the following paper, by 

 Dr. Leidy, reported in favor of publication in the Proceedings. 



On the Fossil Horse of America. 



By Joseph Leidy, M. D. 



The fact of the existence of fossil remains of the horse in America has been 

 generally received with a good deal of incredulity, arising, perhaps, from the 

 mere fact being stated of their having been found, often without even mention- 

 ing the associate fossils, and in all cases, previous to Mr. Owen,* without des- 

 cribing the specimen. At present their existence beiog fully confirmed, 

 it is probably as much a wonder to naturalists as was the first sight of 



* Zoology of the Voyage of the Beagle, part 1. By R. Owen, Esq. London, 



1840. 



