downing] A CLASS OUTLINE 229 



prey or their enemies by the sense of smell. Now we use the 

 sense of sight. Can you tell a rabbit's track ? a squirrel's ? Can 

 you tell in which direction the dog is travelling from his tracks? 

 Draw a dog's track. Can you tell from a rabbit's or squirrel's 

 tracks which way the animal was going? Read How Bunny 

 Writes His Autograph in Gibson's Sharp Eyes. 



Notice that a dog's nose is cold and moist. Try this experi- 

 ment with the school and then see if they can tell why the dog's 

 nose is wet. With a clean handkerchief, wipe dry the surface 

 of the tongue. Sprinkle a pinch of sugar on the dry surface and 

 keep the mouth open. You will find that no sweet taste is to be 

 noticed until the saliva has run down upon the tongue and dis- 

 solved the sugar. The terminal organs of the sense of taste are 

 so constructed that only substances in solution can affect them. 

 This is true also for the organs of smell. The gases which a 

 flower gives off dissolve in the moist mucous membrane of our 

 nose and then we smell the perfume. What other animals have 

 moist noses? Do they have a keen sense of smell also? 



Notice the reading of the thermometer in the school room. 

 Then wrap a moist cloth about the bulb. In a few minutes note 

 the reading again. Now can you tell why the dog's nose is cold? 



Lesson XII. Protective Color and Habits. — The animal's 

 weapons and senses are not its only means of protection. What 

 is the color of the wild hare in winter ? What during the rest of 

 the year? What is the purpose of this change of color? What 

 is the color of the squirrels in your neighborhood? Where do 

 they live? What is the color of the tree trunks? What is the 

 color of the deer's coat? Of the fawn's? Can you think of other 

 animals of your own region that are protectively colored? 



What is the color of a skunk? Of a hornet? Some of these 

 animals that have a sting or other adequate means of defense are 

 brightly colored in order to be conspicuous. The bright color 

 serves to advertise their disagreeable qualities. Some of the 

 great cats illustrate well another phase of coloration. They are 

 colored like their surroundings not to save them from attack but 

 so they can creep up without detection and capture their prey. 

 The lion, inhabitant of the desert regions, has a coat of sandy 

 hue. The tiger, lurking among the reeds and rushes of the river's 

 margin, is striped with alternate bands of yellow and black. The 

 leopard, jaguar and many other forest inhabiting animals, are 

 mottled to match the sunlight and shadow on the forest floor. 



Certain habits of these common pets, relics of their wild 

 ancestry, are protective in their purpose. Do you ever see a 



