MAMMALIA 463 



in the state of Texas alone, were killed 98,600 wolves and wild 

 cats, including 53 panthers and 22 leopards. And yet when 

 the domestic animals are properly protected, most of these forms 

 live upon rabbits and other rodents, and insects. The balance in 

 nature is so complex that we cannot prophesy all the results that 

 may come from the destruction of a species or the introduction 

 of a new one. Our most pressing problems relating to noxious 

 animals lie in the control of the rodents, the insects, and the 

 sporozoa. 



466. Supplementary Topics for Field and Library. 



1. Enumerate the native species of mammals known by you 

 to be found in your locality, and determine to which of the 

 orders of mammals they belong. Are you impressed that the 

 number of native species of mammals is large or small as com- 

 pared with other animals ? Are the individuals of these species 

 numerous or not ? How do you account for the facts you have 

 discovered ? 



2. Enumerate the species of domestic mammals in your lo- 

 cality. Are they related to any of the native species? Trace 

 the history of some of the most important domestic types. 

 What do you know of the mammals domesticated in other 

 parts of the earth? 



3. Make a report on the ruminants: their habits, their dis- 

 tribution over the earth, and their uses to man. 



4. Make an investigation of the breeds of cattle, or horses, or 

 goats, or sheep. Find out some of the strong and weak points 

 of each breed. 



5. What is known of the geological history of the horse 

 family ? Is the horse a native of America ? 



6. What is the history of the introduction of rabbits into 

 Australia ? Can you cite any similar history of rodents in this 

 country ? 



7. Report on furs and fur-bearing animals. What is the 

 present state of the seal fisheries of our Pacific coast? What 

 steps are necessary to the preservation of the seal? On what 

 zoological grounds are these steps necessary? 



8. Make a report on the habits and instincts of the beaver. 

 Describe the nature of its social life. 



