A Guide to the Zoolopical Collections in the 



the animal kingdom we find many groups of animals, e.g., 

 the Sponges, which being devoid of organs of sensation and 

 beino- devoid of the power of voluntary movement were 

 for a long time classed as plants, and when we descend to 

 the lowest foundations of the vegetable kingdom we find 

 many microscopic plants, which being endowed with the 

 power of spontaneous motion were at first classed as 

 animals. 



The broad distinction that holds good, in the main, 

 throughout the two kingdoms is that Plants live upon and 

 build themselves up out of inorganic substances, while 

 Animals can only live upon and build themselves up out 

 of already-made organic substances. 



In other words, in the cycle of Nature, Plants are manu- 

 facturers of organic substances for the consumption of 

 Animals. 



All Animals and Plants are built up of cells. 

 [The word "cell," as used in biology, means a micros- 

 copic mass of semi-fluid living-substance or protoplasm 

 usually containing a denser body known as the nucleus, 

 and sometimes surrounded by a membrane or wall : the 

 semi-fluid living jelly or protoplasm of which cells are 

 made, is an extremely complex chemical compound of 

 Carbon, Nitrogen, Oxygen, Hydrogen, Sulphur, etc.]. 



For purposes of classification Animals are divided into 

 (i) Protozoa^ or animals that consist of a single cell, and 

 (2) Metasoa, or animals that consist of an aggregate of 

 cells. 



The Metazoa again are sub-divided into (i) Ccelen- 

 terata, or animals in which the cavity of the body is 

 formed entirely by the intestine ; and (2) Ccelomata, or 

 animals in which there is a distinct body-cavity through 

 which the intestinal tube runs, — like a lamp-chimney 

 through a lamp-globe. 



The Coelomata are further sub-divided into several great 

 phyla or family unions, namely, (i) the Platyheltninthes 

 or Flat-worms, of which the common Liver Fluke may 

 be taken as a type ; (2) the Nemathelminthes or Non- 



