TfiE^FAUNA OF THE ZOO 



water sponge in the canal which cuts the gardens in two. 

 The Jelly-fish and Sea-anemones at any rate the latter 

 have 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 

 Chsetognatha 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 vertebrae, 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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