132 t)R. E. CRISP ON flilfi GALL-BLADDER [April 8, 



generally, three at least of these portions being recognizable, namely, 

 the dental, angular, and articular. The anterior and posterior 

 mental spines are conspicuously developed, the line of suture of the 

 two halves of the jaw being entirely obliterated. As in the similar 

 palatine dentition, the enamelled coverings of the teeth are not struc- 

 turally connected in the middle line. 



The zygomatic ov jugal bone (0), to which the lower jaw appears 

 to be exclusively articulated, is here very fully developed. This is 

 the OS quadratum of birds. The anterior inferior end is hollowed 

 out for the reception of the articular process of the jaw, the upper 

 portion being flat and directed inwards so as partly to overlap the 

 border of the sphenoid. 



Immediately below the above are two small osseous appendages', 

 which Bischoff regards as opercular bones. The superior one (P) is 

 styliform, and, from its position, seems to me to represent the sym- 

 plectic bone, hitherto supposed to be peculiar to fishes. The infe- 

 rior bone (Q) is comparatively broad, and by its position appears to 

 correspond with the pre-opercular bone of the same class. Behind, 

 below, and in ligamentous union with these bones, the hyoid appa- 

 ratus (R) is connected. It here consists simply of two large, con- 

 verging, curved cylinders, slightly flattened at either end, and which, 

 stretching forwards and downwards, unite together anteriorly in the 

 middle line. Bischoff calls them, taken together, the tongue-bone ; 

 but it appears to me that the two divisions are homologous with the 

 a]^ohyals, or anterior cornua of the hyoid. 



4. On the Situation, Form, and Capacity op the Gall- 

 bladder IN the Vertebrata; on its Absence in certain 

 Animals; and on the Colour op the Bile. By Ed- 

 wards Crisp, M.D., F.Z.S,, etc. 



In 1853 I read a paper at the London Physiological Society upon 

 the Bile and Gall-bladder, but at that period my experience was 

 comparatively limited. A very short abstract only of this commu- 

 nication was published in the 'Lancet' and 'Medical Times,' 1853. 



As mentioned in the charter of this Society, one of the objects of 

 its founders was the cultivation of anatomy and physiology — de- 

 partments of zoology of much greater importance, as I believe, to 

 the good of mankind than the external characters of animals, or of 

 their too often fanciful division into genera and species. I therefore 

 make no apology for the introduction of the present communication, 

 which is partly physiological. 



Every circumstance connected with the secretion, quality, and 

 quantity of the bile — a fluid of such vast importance in the animal 

 economy — must interest the zoologist ; and, as I have stated in my 

 papers " On the Causes of Death of the Animals dying in the Society's 

 Collection" ('Proceedings,' 1860, pp. 175, 190) that diseases of the 

 liver, and consequently derangements of the biliary secretion, are very 

 frequent, the investigation, I think, must be profitable to the Fellows 



