586 M. L. DOLLO. 



To sum up, then, I believe that I have discovered in Lacer- 

 tilia a real malleus, the homologue of that of Mammalia, and 

 with that fact as a starting-point it appears that the conclu- 

 sion may be formed that the quadrate of Mammalia is not to 

 to be sought for amongst their ossicula auditus. In this 

 respect, therefore, M. Albrecht's theory receives confirmation, 

 although it will be necessary that it should be slightly modi- 

 fied. Instead of the statement with regard to reptiles :^ 



Columella = malleus + incus + os lenticulare + stapes, the 

 matter must stand thus : 



Columella = incus + os lenticulare + stapes. 



II. 



Is the quadrate of M. Albrecht really the homologue of the 

 quadrate of Sauropsida ? 



Such is the second question to be considered. Before going 

 further it will be well to consider what are reasons given by 

 M. Albrecht in favour of his interpretation. They are three 

 in number. 



1st. The quadrate of Mammalia, since it could not find 

 place in their interfenestral chain, must be to be found else- 

 where. 



2nd. The glenoid cavity ought still be found in the quadrate 

 bone. 



3rd. There are a certain number of instances known in 

 which the squamous portion of the temporal bone of man, or 

 of the primates, is divided into two parts. 



a. The squamous bone properly so called. 

 [5. The zygomatic portion. 



It appears to me that two further methods of inquiry should 

 be employed to make certain whether the quadrate of M. 

 Albrecht is a real quadrate or not. These are : 



1st. The examination of its connections. 



2nd. The study of its development. 



' I'. Alhrrcht, loc. cit.., p. 15. 



