172 DR. G. BAUER. 



mosal is divided into two portions : the zygomatic process and 

 the "scale." In the zygomatic process Albrecht sees 

 the quadrate of the rest of the Vertebrates. He finds 

 the same conditions in a newborn horse, and in the squa- 

 mosal of the right side of an idiot twenty-one years old. 



Dollo uses the same arguments : first recapitulates Albrecht's 

 results, and then describes his own researches. He asks the 

 question : Is it possible that the quadrate can form a part of 

 the interfenestral chain of auditory ossicles ? If we succeed 

 in finding a Vertebrate in which the lower jaw consists of the 

 six normal elements, and in which, moreover, a true quad- 

 rate and a malleus are present, then it is impossible that the 

 quadrate can be homologous with any of the auditory ossicles. 

 Therefore — 



(1) It cannot be compared with the malleus, since this is 

 present, and (2) it would be impossible to identify it with 

 one of the remaining auditory ossicles, because it would be 

 outside the malleus, and touch none of the other auditory 

 ossicles. 



It depends, therefore, on finding a malleus which shall fulfil 

 the above conditions. Dollo maintains that he has found in 

 many Lacertilia (Leiolepis, Uromastix, and their allies) 

 a skeletal piece which has the morphological value of a malleus. 



Dollo' s arguments in support of this are : 



1. The piece has the form of a malleus, and all the charac- 

 teristic parts of one can be distinguished. 



2. The piece has the same connections: it is fixed to the tym- 

 panic membrane in such a way that the manubrium is parallel 

 to the membrane. At the side, in the region of the cervix, it 

 is connected by cartilage with the rest of the auditory ossicles ; 

 and with the quadrate it stands in the same relation as the 

 malleus of Mammals with Albrecht's " quadrate." 



3. It is connected with the articulare of the lower jaw by a 

 malleo-articulare ligament — Albrecht's extra-mandibular por- 

 tion of Meckel's cartilage. 



4. It can scarcely be doubted that this malleus is identical 

 with that described by Peters for the crocodiles. 



