PREFATORY NOTE. 



IN the following pages the most promhaent characters of the larger 

 groups have alone been given, in order to afford a bird's-eye 

 view of the Animal Kingdom. In learning the characters, whether 

 of Sub-Kingdoms, Classes, Orders, Families, Genera,, or Species, the 

 student has always to bear in mind that he is dealing with definitions 

 which apply not necessarily to every individual in the group defined, 

 but only to the bulk of the members composing it. The absence of 

 lines of demarcation in Nature makes it impossible to frame rigid 

 definitions. Thus, to affirm of the Protozoa that they are unicellular 

 and do not reproduce sexually, while true of the class as a whole, is 

 not true of every individual Protozoon, a few of the higher members 

 violating the statement by shading off indefinitely into the Metazoa. 



Common names have been given wherever possible. 



A Genealogical Table, and a few other additions, have been made 

 to the present Edition. 



GENEALOGICAL TABLE. 



The accompanying Genealogical Table (modified from Herdman 

 after Hseckel) is an attempt to summarise diagramatically the theoretic 

 history of the Animal Kingdom. The line traced from Protamseba 

 up to the name of any aiiimal or group of animals mentioned in the 

 table, indicates the probable course of its evolution. The proportionate 

 lengths and angles of the lines roughly show the amount and nature 

 of the evolution in each case; a line drawn downwards representing 

 degeneration. The larger groups are enclosed in dotted lines. 



The student is advised to persistently copy the Table until 

 he is able to reproduce, at least, the more important parts of it 

 without help. 



