2 SOUTH AFRICAN MAMMALS 



of the numerous text-books on Zoology if he wishes to 

 probe more deeply into the subject. 



Animals may be classified, commencing with the lowest 

 forms and ascending to the highest; or the reverse 

 method may be adopted. The latter is the system used 

 in this sketch, as the only comprehensive modern work 

 dealing with South African mammals is classified in this 

 way. The following is a more complete list of the Sub- 

 Kingdoms into which the Animal Kingdom has been 

 divided: Vertebrata (backboned animals), Tunicata (sea- 

 squirts, &c.), Mollusca (mussels, snails, &c.), Molluscoidea 

 (moss-corals and \a,mpshel\s),Art]iropoda (lobsters, crabs, 

 and insects), Vermes (worms), Echinodermata (starfish, 

 sea-urchins, &c.), Coelenterata (sponges, corals, and jelly- 

 fish), and Protozoa (the lowest forms of animal life, 

 including the germs of many diseases). 



VERTEBRATE ANIMALS. 



The Vertebrates, as already stated, constitute the 

 highest group of animal life, and are mainly charac- 

 terized by a vertebral column or backbone, which consists 

 of a number of bones called vertebra, joined together by 

 ligaments. Through the centre of the backbone runs a 

 canal containing the spinal marrow (a cord of nerve 

 tissue running from the brain to the end of the column). 

 On the opposite side of the backbone or spine there is a 

 much larger cavity, formed by the ribs and breastbone, 

 which contains the heart, lungs, liver and intestines, &c. 



Vertebrate animals are still further characterized by 

 the possession of not more than four limbs, and by the 

 fact that the jaws are situated one above the other, or 

 " upper and lower." 



