DRE EAUNAS Ob tH sZ00 
water sponge in the canal which cuts the gardens in two. 
The Jelly-fish and Sea-anemones—at any rate the latter 
—haye constantly been on view in the Fish House. The 
Mollusca are present in the shape of slugs and snails 
upon the paths and occasionally of large tropical land 
shelled forms in the Insect House. The Appendiculata, 
including the vast series of organisms ranging from the 
earthworm and its kindred at the lowest step of the series, 
and culminating in the insects, are plainly well repre- . 
sented. The Nematoidea, or thread worms, lurk as para- 
sites among the caged animals, as do also certain of the 
members of the seventh great phylum, the Platyhelmia. 
The Echinodermata (starfish, sea urchins), will not be 
found. Nor does the collection contain examples of 
two groups of marine or terrestrial ‘“‘ worms,” the 
Chetognatha and Nemertina. Finally the Chordata 
include the Vertebrata, with which we are concerned 
here ; and it is this group which the Zoological Society 
considers it is its business to exhibit with the greatest 
possible lavishness in variety of genus and species. It 
is worth bearing in mind that the animal life of this 
planet is constructed upon such few types while its 
variety in modifications upon these types is so enormous. 
What holds good of animal life in general is also true 
of the vertebrata alone. It will be plain from quite a 
cursory inspection of the collection that all vertebrata 
arrange themselves round at most five types, viz. 
mammals, birds, reptiles, amphibians, and fishes. It 
behoves us, however, first all of to enquire what a verte- 
brate is; we can then proceed to consider the various. 
types of vertebrates offered for our studies in the gardens 
of the Zoological Society, and other gardens abroad. 
As the name denotes, the vertebrata have a backbone, 
a series of bones known as vertebre, which is dorsal in 
position, and underlies as well as enwraps the brain and 
spinal cord, the central nervous system. This backbone 
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