EXPLANATION OF THE CHART OF THE ORDERS OF MAMMALS. 



To the beginner in Natural History studies, the Order is the master-key to classification. 



This Chart is based on the well-known fact that in the pursuit of a difficult study, any scheme 

 which properly and truthfully appeals to the eye is an aid both to the understanding and the mem- 

 ory. It shows the relative importance of the various Orders of Mammals, but not their relative 

 sizes, based on the number of species in each, as has been done later on with the birds. If number 

 of species were given precedence over economic importance, the Order Glires would dominate, and 

 the Order Ungulata would appear small and insignificant. 



It is impossible to construct a diagram which will show correctly the relations which the various 

 Orders bear toward each other, anatomically. This is because some Orders are characterized by 

 their teeth, some by their feet, or hands ; others by their wings, and two by their mode of producing 

 their young. 



It will be noted that: 



The Primates, of the tree-tops, have the highest position. 



The Cete, which in some respects are the lowest of the Mammalia, occupy the lowest position. 



The Bats are shown in mid-air, and the Insectivores appear under ground, where they live out 

 their lives. 



The Seals and Sea-Lions appear both on the shore and in the sea, and the Sirenians are located 

 in an estuary. 



The Ferae, Glires and Ungulata spread throughout the whole visible earth, covering forest and 

 plain, sea, pond and stream, from the sea to the most distant mountains. 



The Monotremates, or egg-laying mammals, are quite apart from all other land mammals, and 

 appear low down, near the home of the ducks, as shown on the bird chart. The space allotted 

 to this strange Order has been made egg-shaped, to suggest the leading characteristic of its 

 members. 



