Vertebrata. Zoological Collections, 369 



described in accordance with the nomenclature of Dr Barclay. After a 

 brief exordium stating the objects of the paper, as just described, and an 

 explanation of some of the terms employed, the author proceeds to detail 

 the proportionate dimensions of the bones constituting the entire skeleton^ 

 of the Bactrian camel, in the following order, viz. : the head ; the vertebrae, 

 classified in the usual manner ; the sacrum ; the tail ; the ribs ; the cavity 

 of the thorax, and the sterimm ; the scapula ; the pelvis, and the limbs. 

 The height, the breadth, and tlie basilar length of the cranium, Dr Adams 

 states, ai-e very nearly in the proportion 1, % 4. The common difference 

 in the palatal, the coronal, the basilar, and the extreme length of the 

 cranium, is the breadth of the cranium at the temporal fossae : these lengths, 

 in the animal examined, being, respectively, 12, 15, 18, 21 inches. The 

 lateral extent of the atlas is equal to the distance between the inner margins 

 of the orbits. The greatest elevation of the spine is at the third dorsal 

 vertebra ; the extreme length of that bone equalling the greatest extent of 

 the pelvis towards the mesijil plane. The longest of the twelve ribs are 

 the seventh and the eighth ; their length equals the greatest extent of the 

 scapula. The sum of the lengths of the twelve ribs is about ten times that 

 of the longest rib. The dimensions of the cavity of the chest agree with 

 those of the separate bones of the body ; thus, the greatest width of the 

 chest is equal to the greatest length of the head. The breadths of the 

 pelvis, rostrad, (measured towards the front,) from the acetabula, are even 

 numbers of proportional parts. The breadths, caudad, (measured towards 

 the tail,) from the acetabula, including the acetabular breadth itself, are odd 

 numbers of proportional parts. The chief dimensions of the pelvis are 

 identical with the chief dimensions of the head ; thus, for example, the 

 greatest dimension of the pelvis, being through the mesial plane, is equal 

 to the greatest length of the head. The lengths of the four long bones of 

 the atlantal (fore) limbs, independent of processes and elevations, are 

 consecutively as the numbers 22, 28, 20, 6, — sum, 76. The similar lengths 

 of the four long bones of the sacral (hind) limbs are consecutively as the 

 numbers 28, 23, 20, 5, — sum, 76. The author observes, in conclusion, 

 that, from the exposition given in the paper, it appears that, throughout the 

 dimensions of the bones of the Bactrian camel there is such an agreement, 

 that many of the dimensions are continued proportionals, and that the 

 mutual relations of nearly all admit of a very simple expression ; and he 

 states that corresponding relations have been found to prevail in the bones 

 of every species of animal he has examined. From the full verification of 

 these observations in the osteology of other animals, it will result, he infers, 

 that zoology is susceptible of a classification established on the fixed basis 

 of number, that the tissues by which the bones are moulded are also of 

 determinable proportions, and that, consequently, the development of the 

 ])arts of organized bodies, &c. afford a wide scope for numerical as well as 

 for physiological inquiry. 



The various proportions are minutely exhibited in twenty-eight folio 

 tables ; the first column of each giving the actual dimensions of an individual 

 camel, and those measurements being in the next column adjusted to the 

 normal proportion, on the assumption, that the aberrations in the form of an 

 individual animal, from the perfect form of its species, may be at least as 

 great as the inequalities of the right and left sides of that individual itself. 

 The numbers assigned to the normal proportions, however, are regarded 

 merely as aproximations. 



Note on the Ear of Birds. — At first sight, it might be supposed, that, in 

 the tympanum of birds, there is only one orifice leading into the labyrinth ; 

 but it is not so ; for this single opening is merely the entrance into a short 

 canal, at the bottom of which are two holes, separated by a spiculum of bone, 

 and corresponding to the fenestra ovalis and fenestra rotunda in the mammalia. 



VOL. III. 3 A 



