26 
CENTRAL HALL. 
fications of the skeleton. The Apteryx possesses the smallest, 
and the Frigate-bird the longest bones of the wing, the corre- 
spondence of which can be readily traced by means of the 
labels attached to them. The under surfaces of the skulls of 
various birds are shown with the different bones coloured to 
indicate their limits and relations ; these are followed by a 
series of the different types of sternum or breast-bone. 
The second wall-case contains further illustrations of the 
anatomy of birds. In the left-hand part a series of wings of 
birds displaying the form characteristic of different groups; 
while above them are a few of the different types of tails, 
supplementing the series of tails in the table case. Very 
instructive is a series of skins of white chickens of the same 
brood at different ages displaying the gradual replacement of 
the down by the adult plumage. 
The table-case in the middle of the bay contains illustrations 
of the external characters, the beak, the feathers, and the tail, as 
well as of the fore and hind limbs, or wings and feet. By the aid 
of the explanatory labels, the essential characters and the prin- 
cipal modifications of all these parts can easily be followed. 
Two cases on the walls at the entrance to bay V. illustrate 
the leading modifications of the eggs of Birds, and their differ- 
ences in structure, number, form, size, texture of surface, and 
colour. On the side of the main staircase opposite are speci- 
mens illustrating the parasitic habits of some Guckoos and 
certain other Birds ; while near by is a remarkably fine series 
of the eggs of Cuckoos with those of the Birds among which 
they were respectively deposited. -On the opposite (east) side 
of the staircase the visitor will find a case showing the remark- 
able variation in colouring and markings displayed by the eggs 
of the Guillemot. 
Bay IV. The fourth bay on the west side of the hall exhibits the 
Genera^i strnc leading peculiarities in the structure of Eeptiles and Amphi- 
Reptiies and bians. Owing to the large number of groups in the former 
Amphibians, class now extinct, many fossil specimens, or plaster reproduc- 
tions of the same, are shown. The wall-case on the south side 
of this bay illustrates the different ordinal groups of Eeptiles — 
living and extinct. Very instructive are the skeletons of 
Tortoises and Turtles, showing the relations of the vertebrae 
