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, GrocrapuHicaL Dis- 
TRIBUTION. The past history of animal life is in a 
similar manner called GroLocicaL 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. 
