OSTEOLOGY OF BIRDS 1/7 



Between the orbital peripheries the frontal region of the skull 

 in both cock and hen of these fowls is, as I have said, rather broad, 

 more so in the former than it is in the latter sex, but this is only 

 due to the greater size of the skull in the male, a matter we will 

 deal with further on by presenting tables of measurements of these 

 and other parts. It is this region that mounds up and exhibits those 

 extraordinary perforations in the domestic variety known as the 

 Polish fowl, and which supports those curious lx)ny protuberances 

 in the Horned fowl, another variety, the product of man's selective 

 development.^ 



A great authority, in alluding to such monstrosities as compared 

 with the characteristics of normal skulls in his review of this part 

 of the avian skeleton in general, says that " the spherical bony cyst 

 above the forepart of the cranium in a variety of common fowl 

 may be omitted, though this, like the stunted mandibles of some 

 varieties of pigeon, may rather rank among the phenomena of 

 pathology." 2 



Turning now to the lateral aspect of our skull of G . b a n k i v a 

 [fig. 2], I find that I have above already sufficiently dwelt upon the 

 premaxillary, nasal, and lacrymal elements, and we now have 

 brought fully into view the unusually delicate zygoma of this fowl, 

 connecting the quadrate with the nasal bones. By the aid of a 

 lens the fine sutural traces upon it showing the landmarks among 

 the quadratojugal, jugal, and maxillary divisions, can yet be made 

 out in the skulls of these adult birds. 



The peripheral margin of the orbit is seen to be almost a subcir- 

 cular arc, as it sweeps from the lacrymal bone to the extremity of 

 the sphenotic process, while its edge is found to be finely serrated 

 for its posterior moiety. Large and capacious, the external osseous 

 ear conch is of an elliptical outline, permitting a plain view of its 

 base, where exist those several small perforations which lead to 

 the middle or internal ear, as well as the larger Eustachian opening, 

 situated anterior to them. Above and in front of this aural aper- 

 ture, we are to observe the two lateral processes, the sphenotic above 

 and the squamosal below, so characteristic of all skulls of Galli- 

 naceous birds. Here in the male Jungle fowl, the sphenotic process 

 is somewhat the longer of the two, is compressed from side to side, 

 and within, continuous with the alisphenoidal surface of the 



' Darwin, C. Animals and Plants under Domestication, i : 320, fig. 36. 



'Owen, R. Comparative Anatomy and Physiology of Vertebrates. Lond. 1866. 2:65, 

 in this connect'on sec olso Teg-tmeier. Zool. Soc. Lond. Proc. Nov. 1856, and- 

 L Geoffrey St Hilaire. Histoire generale des anomalies, i: 287; also M. C. Dareste, 

 ■Recherches sur les conditions de la vie. etc., Lille. 1863. p. 36. 



