186 MR. W. K. PARKER ON THE OSTEOLOGY 



in the possession of Dr. Clarke, of Cambridge. Again, it would be interesting to know 

 whether the wild Pelican has any non-pneumatic bones ; also the Horn-bill. I should 

 suppose not, however. The economy of osseous substance in the skeleton of Pelecanus 

 onocrotalus is so great that Dr. Fritsch of Prague declared to me, with great fervour, 

 of a specimen in his collection, that " you lay it on your hand, and it actually weighs 

 nothing." Now, in the " Pluvialinae " (e. g. Vanellus cristatus, Charadrius hiaticula, &c., 

 only the cranium proper contains air. Their long-billed, probing relatives (e. g. Nume- 

 nius arquatus, Tringa cinclus, Limosa rufa, Totanus calidris) have a similar state of the 

 skeleton. The Gulls (e. g. Larus canus, Gavia ridibunda) and the Mergansers (e. g. 

 Mergus alhellus) have the head and the vertebrpe, as far as to the thick part of the 

 sacrum, pneumatic : in these birds the ribs, the sternum, and all other parts are fatty. 

 In the typical " Anatinse " (e.g. Querquedula caudacuta, Cygnus olor) the sternum and 

 humerus also receive air. In that near relative of the Pelican the Cormorant, the 

 bones seem to be entirely medullary. Many other Palmipeds have very fatty skeletons, 

 especially the Divers, from the little Dabchick {Podiceps europeeus) to the huge Pen- 

 guins. In the Pluvialine and Tringine birds the thick branches of the trigeminal nerve 

 are imbedded in fat-cells ; so that the facial part of the skull is oily. In the larger 

 "Waders" there are more pneumatic bones. In the Herons the tail-bones, the 

 scapulae, clavicles, and coracoids, and all the limb-bones contain marrow, except the 

 humeri. The furculum contains air, however, in the Adjutant and the Balaniceps, as 

 also do the caudal vertebrae. The Trumpeter {Psophia) agrees with the Heron, save 

 that in it the broad coracoids are pneumatic. In the Hawks (Falconinse) even the 

 OS femoris contains air, but not, as a rule, the caudal vertebrae. In the Owl the thigh- 

 bones are oily, as they are in most of the arboreal " Perchers," "Creepers," and 

 " Climbers," although in them the cranial, facial, and trunk-bones are pneumatic. 



In birds that "do business in great [salt] waters " we find the most oily skele- 

 tons; and yet we all well know that some of the most graceful aerial birds belong to 

 this class, both among the "Waders," " Swimmers," and " Plungers." But the plung- 

 ing Gulls and the wading Plovers are better fliers than many of the beautiful " Ana- 



tinae " that 



" Row their state, with oary feet." 



Yet there is no very definite rule with regard to the connexion between pneumaticity of 

 the bones and power of flight. All the salt-water birds have large nasal or supraorbital 

 glands, for the sake, undoubtedly, of the delicate Schneiderian membrane. The iso- 

 morphs of the Cetacea (the Penguins) might be expected to have a coarse, fatty, non- 

 ornithic skeleton, and they have such a framework ; yet its teleology is as consummate 

 as that of the Humming-bird or the Swift. The. axillary air-cell pushes itself into the 

 head of the humerus internally and below the deep expanded portion, in many birds, 

 especially the " Anatinse "; even where the humerus is medullary, as in Mergus, this 

 large pit still exists, although the air-cell does not enter the bone-cavity. In the Pigeon 



