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 di£ferent 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 pria- 

 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 Cuckoos 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 



torTof ^*""'' ^®^'^^°g peculiarities in the structure of Eeptiles and Amphi- 

 EeptUes and bians. Owing to the large number of groups in the former 

 Amphibians, pi^ss 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 



