14 
CENTRAL HALL. 
Alcoves r d ^^^^ ^^^^^ alcoves round the hall, five on each 
the Hall. side, are ( with the exception of one reserved for the exhibition 
of recently acquired specimens of especial interest) devoted to 
the Introductory or Elementary Morphological Collection, 
designed to teach the most important points in the struc- 
ture of certain types of animal and plant life, and the 
terms used in describing them. This has been called the 
" Index Museum," as it was thought at one time that it 
would form a sort of epitome or index of the main collections 
in the galleries ; but the name does not exactly express what 
it has developed into. It is really more like the general 
introduction preceding the systematic portion of treatises on 
any branch of natural history. The space being limited, the 
number of specimens is necessarily restricted, probably to the 
advantage of the student, at all events in the earlier part 
of his career. In examining this collection the visitor should 
follow each case in the usual order of reading a book, from 
left to right, and should carefully study all the printed 
explanatory labels, to which the specimens are intended to 
serve as illustrations. 
The bays on the west side (left-hand on entering the hall) are 
■ devoted to the Vertebrated Animals, or those possessing a 
" backbone." In E"os. I. and II. are shown the characters of 
the Mammalian modifications of this type. The wall-cases of 
No. I. contains specimens showing the bony framework (internal 
skeleton) of Mammals. 
Bay L In the first case (south side of the recess) will be seen a 
Mammais° complete skeleton of a good example of the class — a large 
monkey, with all the bones separated, laid out on a tablet, and 
their names affixed to them. Below is a skeleton of the 
same animal articulated, or with the bones in their natural 
relation to each other, and also named. By examining these 
two specimens a fair idea may be obtained of the general frame- 
work of the body of animals of this class. In other parts of the 
case are placed examples of modifications of the skeleton to 
suit different conditions of life. 
1. Man, showing a skeleton adapted for the upright 
position. 
2. A Bat, or flying mammal, in which, by the great elonga- 
