STRUCTUKE OF BIRDS. 25 



by sections to consist of a solid mass of hair-like epidermic 

 fibres. 



7. The horns of Oxen, Goats, and Antelopes, consisting of a 

 hollow conical sheath of horn, covering a permanent projection 

 of the frontal bone (the horn-core). 



8. The antlers of Deer, solid, bony, generally branched, projec- 

 tions, covered during growth with soft hairy skin, and in most 

 cases shed and renewed annually. 



On the wall is arranged a series of antlers of the Stag 

 or Eed Deer (Cermis elaphus), grown and shed (except the 

 last) in thirteen successive years, showing the changes which 

 took place in their size and form, and the development of the 

 branches, or tines, in each year. In old age the number of 

 these tines tends to diminish. 



On the north side of the table-case are dissections of the 

 principal internal organs of Mammals. 



Bay No. III. is devoted to the class of Birds. An Albatross Bay iii. 



(Biomedea exulavis) mounted with the wings expanded shows <*6neral 

 N , . , , 1 , 1 ■, ■ 1 ■, . f . ,, stnictnre 



the most important characters by which a bird is externally of Birds. 



distinguished from other animals. The body is clothed 

 with feathers, which (in the majority of birds), by their great 

 size and special arrangement upon the fore-limbs, enable 

 these to act as organs of flight. The mouth is in the form of 

 a homy beak. A nestling Albatross shows that at this stage of 

 its existence the bird is not clothed with true feathers, but with 

 soft down, which serves to keep the body warm, although it 

 confers no power of flight. An Emu and Apteryx in the lower 

 compartment of the case display the exceptional condition (found 

 only in a comparatively few members of the class) of birds with 

 wings so small as to be concealed beneath the general feathery 

 covering of the body, and quite useless. In the Penguins, 

 of which two species are shown in the case, the wings are 

 reduced to the condition of fins, and are only serviceable for 

 progress through water. 



In the first wall-case the principal features of the skeleton of 

 the class are shown. Sections of bones exhibit the large air-cavi- 

 ties within ; a complete skeleton of an Eagle, with the bones sepa- 

 rated and named, and mounted skeletons of the Ostrich, Penguin, 

 PeUcan, Vulture, Night-Parrot, Fowl, &c., show the chief modi- 



