STRUCTURAL RELATIONSHIP 



293 



Reptiles 



3000 



'Amphibians 



700 



Thread 

 Flat fformsr^'^ 



Protozoa 



4000 



Fia. 107. Diagram showing the general relations of the chief divisions of 

 the animal kingdom. The number of species belonging to each is roughly 

 approximate only. (Galloway.) 



