MK. W. K. PAEKER ON THE OSTEOLOGY OF THE KAGU. "505 



the sharp anterior spurs of the palatines and of the raaxillaries. As the maxillary of the 

 bird has cost me more trouble than any other part, I shall take some pains to describe 

 it, especially as the Kagu and its relatives have this part in a very instructive condition. 

 Here the strictest watch has to be kept, lest the mind should be deceived by external 

 resemblances, and by actual function of the parts ; nothing but a study of the develop- 

 ment of the face can give any solution of this difficulty. In the first place let it be 

 noted that the maxillary of the Bird is extremely like that of the typical Fish, being 

 secondary in so great a degree to the premaxillary, and lying within and behind it ; the 

 manner, also, in which the palatine stretches forwards to the front of the face and 

 articulates with it is very ichthyic. But the maxillary of the Bird for a long while 

 seemed to me to be merely a very inordinately developed septo-maxillary (the so-called 

 turbinal of the Lizai'd) ; so that the Lacertian relationship appeared to be that which was 

 most e^ddent. Now, however, I have no doubt about its being truly the maxillary of the 

 other Vertebrata ; but I do see in it also the Lacertain septo-maxillary in a high state 

 of development in many cases, but continuous with the true maxillary. But comparison 

 of the Bird's maxillary with that of the cold-blooded Vertebrata (excluding the Croco- 

 diles) fails to give any explanation of its meaning; and it is only by comparing it, 

 also, with a series of Mammalian counterparts that it can fully be understood. Perhaps 

 the first thing that strikes the eye in the anterior part of a bird's palate is the large 

 azygous " anterior palatine foramen ; " this is quite unlike what is seen in Mammals 

 generally. In the Bud the space between the dentary and palatine plates of the pre- 

 maxillary is filled up by the sharp wedge-like fore end of the maxillary; whilst the 

 " anterior palatine foramen " is seen to be merely the space between the palatine plates 

 of the premaxillaries. The Pangolin {Manis) and, especially, the Hedgehog [Erinac'eus) 

 explain this, the symmetrical passages being almost filled up by the wedge-like anterior 

 ends of the maxillary palatine plates. But in the Pangolin, and also in the Coati 

 (Nasua fusca), the palatine plates of the premaxillaries are bowed out in some degree, 

 forming a third opening in their fore-palate. This structure is precisely the morpho- 

 logical link wanting to make the Bird and the Mammal hang together here. In the 

 Pangolin the palatine plate of the maxillary is one continuous, nari-ow, obliquely scooped 

 sheet of bene, attached by "harmony" to the palatine plates of the palatine behind, 

 and wedged in between the premaxillary forks in front. In the Hare [Lepus timidun), 

 however, four-fifths of this plate is absent; and behind only does the maxillary send 

 inwards an elegant, subquadrate, pedate plate to meet its fellow of the opposite side, 

 and to be underlain behind by the much feebler palatine plates of the palatines. 



In the Bird the part answering to the fore end of the Pangolin's palato-maxillaiy plate 

 is differentiated from the hinder part, is very narrow, and entirely fills up the space 

 between the premaxillary forks. Behind, tlie Biid's maxillary developes the exact 

 counterpart of the palato-maxillary plate of the Hare ; and this part, instead of keeping 

 to the palatal floor, as in the Hare, ascends into the nasal labyrinth, occluding it in 



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