INTRODUCTION. 
To a large class of visitors, who desire to find in a zoolog¬ 
ical collection means of instruction as well as amusement, a 
brief statement of the meaning and the relative value of the 
groups into which the animal kingdom is divided by natural¬ 
ists will not be without interest. In order to arrive at a cor¬ 
rect understanding of these, it is necessary to look at the 
animal world, not as a mere mass of living forms bearing hap¬ 
hazard resemblances to each other, but as great family groups 
of beings, formed, more or less, on the same plan, varying, 
it is true, to a vast extent in its mode of expression, but all 
the forms of which are capable of being arranged around 
great centres, each of which presents a somewhat different 
combination of structural peculiarities. 
The first systematic arrangement of living forms was that 
of Linnaeus, and though the researches of later naturalists 
have at times classified them on other bases and in different 
ways, there is now a tendency to return, to a certain degree 
at least, towards the system of the great Swedish naturalist. 
The primary divisions now generally accepted are as fol¬ 
lows :— 
The Vertebrata —possessed of a backbone, as mammals, 
birds, reptiles, batrachians, and fishes. 
The Mollusca —soft-bodied, as oysters, cuttle-fishes, and 
snails. 
The Articulata —formed of rings, as worms, centipedes, 
insects, &c. 
The Coelenterata —as sea anemones and jelly-fishes. 
The Echinodermata —as star-fishes'and sea-cucumbers. 
The Protozoa —as sponges and infusoria—the lowest forms 
of animal life, many of them microscopic and bordering 
closely on the vegetable world. 
It is with the first division only that the collection in the 
Garden has to deal. The Vertebrates^—animals possessing a 
skeleton of bone or cartilage, enclosing cavities in which the 
soft parts of their organization are contained and protected 
from injury—are arranged in five classes , according to the 
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