488 RECORDS. 



In the discussion which followed, Professor Osborn showed 

 that while Clcenodon undoubtedly possesses many precocious 

 bear-like structures there are many difficulties to be pushed aside 

 before it can be considered the direct ancestor of the bear. There 

 are transitional forms for example between dogs and bears, as 

 shown in certain types of teeth (Ampliicyoii)^ while on the other 

 hand there is a marked difference in the size of the brain of the 

 Arctocyonidae and that of the bears ; the brain of the former re- 

 sembling more closely the brain of the marsupials. If the Am- 

 phicyon evidence is of a sufficient phylogenetic value the bear 

 line must have arisen much later than Dr. Matthew believes. 



Dr. Lee also questioned the advisability of ascribing particular 

 functions to specialized structures, a criticism which Dr. Mat- 

 thew met by saying that in this case the relation of structure to 

 function was in the nature only of an hypothesis ; an explanation 

 supplemented by Professor Osborn's statement that in all such 

 cases it is necessary to have some working hypothesis, although 

 each hypothesis is considered merely tentative. 



At the request of Dr. Dean, Mr. Richard Weil was asked to 

 give the main results of his observations on the Development 

 OF THE OssicuLA AuDiTus IN THE Opossum. Mr. Weil finds that 

 both the malleus and incus are derived from the mandibular arch 

 and have no connection with the hypidean, thus confirming the 

 older German view. 



The other papers on the programme presented by Dr. Dean 

 and Dr. Calkins were strictly technical and received only brief 

 mention. 



Gary N. Calkins, 



Secretary. 



REGULAR MEETING. 



November 21, 1898. 



Academy met with Vice-President Kemp in the chair. 

 Reading of the minutes was dispensed with. 



