INTRODUCTION. 3 



Let us now pass to the consideration of the animal 

 kingdom as an organic whole. We may here discern a 

 certain parallel to the organism. The study of the 

 structure of the animal kingdom as such means the 

 arrangement or distribution of animals on the world's 

 surface, or, as it is usually termed, Geographical Dis- 

 tribution. The past history of animal life is in a 

 similar manner called Geological Distribution, whilst 

 physiology finds its parallel in the relationship of the 

 animal kingdom to the inorganic world, for which there 

 is no inclusive term. 



We can at least see this structural parallelism : — 



ORGANISM.— ANIMAL KINGDOM.— 



Morphology. Geographical Distribution. 



Embryology. Geological Distribution. 



By keeping this clearly in mind we are assisted in a 

 consideration of Distribution. 



