360 MR. J. BESWICK PEEEIN ON THE 



the base of the 1st phalanx of the 2nd digit; the ulnar one, into the middle of the 

 ulnar side of the 2nd metacarpal. 



The extensor brevis digitorwm (interosseous) is situated in the interval between the 

 2nd and 3rd metacarpals. It is inserted into the base of the 2nd phalanx of the 2nd 

 digit, and to the ulnar side of the preceding tendons. In the latter respect it resembles 

 the extensor indicis more than the muscle which I have already described under that 

 name. 



The supinator brevis and anconseus present their usual arrangements, as also the 

 remainder small muscles of the manus. 



Caudal Muscles. 



These are well developed, and may be divided into three classes — dorsal, ventral, 

 and lateral. The dorsal muscles are two in number, the levatores caudse superficialis 

 and profundus. 



The levator caitdce superficialis is attached by its proximal end to a deep depression 

 external to the posterior median sacral ridge by tendinous fibres ; distaUy, to the spines 

 of the caudal vertebrae by aponeurotic fibres, which seem to decussate across the median 

 line. 



The levator caiidce profundus is situated on a deeper plane than the preceding, and is 

 partially overlapped by it. It springs from the distal dorsal extremity and excavated 

 surface of the ischium, and also from the lateral aspects of the caudal vertebrae. It is 

 inserted into the fascia covering the bases of the three or four inner feathers of the tail, 

 partly into the superior surface of the caudal gland, and also into the extremity of the 

 median spine of the caudal vertebrae. 



The lateral muscles are three in number : — 



1. Abductor caudae externus. 



2. „ „ anterior. 



3. „ „ posterior (quadratus coccygeus). 



Abductor caudw externus (pubo-coccygeus) arises from the posterior extremity of the 

 OS pubis. It is inserted into the bases of the one or two outer tail-feathers. 



Abductor caudce anterior. — This is a large and extensive muscle. Its lateral edge 

 only, however, can be seen in the figure. It arises from the tuberosity of the ischium, 

 from the apex of the transverse processes of the coccyx, occupying the lateral free aspect 

 of the tail. It is inserted into the base of the outer aspect of the fifth tail-feather. 



Situated upon the bases of the tail-feathers is a large triangular-shaped rump-gland. 



The Ventral Muscles of the Tail. 



These are : — 1. The depressor caudae superficialis. 



2. The depressor caudae profundus. 



3. Dilator caudae rectricum. 



