232 NATURE STUDY REVIEW [7:8— Nov., 1011 



and those vertebrates that do not run well. Note the length of 

 leg and straightness of the leg. 



Lesson XVI. Structure and Use. — How many toes has 

 the cat? Dog? Rabbit- Pig? Cow? Horse? Why can puss 

 walk so quietly? Feel the under side of her feet. Feel the dog's 

 feet. Which are softer? Notice how the kitten uses her claws, 

 how perfectly they are under her control. Where does she keep 

 her claws when they are not in use? Can a dog sheath his claws? 

 Which has sharper claws, a dog or a cat? Why? Recall how 

 the cat and dog held the bone when gnawing it. Why does a 

 horse have a hoof instead of claws? Dogs are used for hunting 

 because they have a keen sense of smell (how did you prove it?) 

 and because they can run swiftly and for a long time. Their 

 relatives the wolves hunt in packs and run down very fleet footed 

 animals. The dog or wolf chasing its prey over rough ground 

 needs the firm hold that the constantly exposed claws give it. 

 The cat does not chase its prey, but, we have seen (first lesson), 

 creeps up stealthily and then pounces on it with a few powerful 

 leaps. How is her structure well adapted to this? To what is 

 the dog's straighter leg adapted? Does the rabbit's structure 

 fit it for a long run or for a few quick leaps ? 



Notice that a hound's body is shaped like this when seen 

 from the front |0 while a squirrel is like this Q . What 

 other animals have a deep narrow body? Think of others whose 

 body is round. Can you tell why a hound's body is narrow and 

 deep like a boat? 



Continual care must be exercised by the teacher lest the 

 nature study degenerates into the observation of unimportant de- 

 tails. Thus merely to have the children count the toes of cats, 

 dogs, rabbits, squirrels, cows and horses is scarcely worth while 

 if the work stops there. Let this be but the first step in the dis- 

 covery of the significant relations between form and length of 

 leg, number and character of the toes, speed and endurance of 

 the animal and its habits of hunting or means of escape. 



Lesson XVII. The Head. — Compare the shape of the 

 hound's head with the shape of the squirrel's. The former has a 

 long pointed head, the latter a compact round one. The reasons 

 for this can readily be appreciated by older pupils. Feel on your 

 own face the point where the lower jaw hinges. This can 

 readily be done as you open and close your mouth. Now 

 feel the cheeks as you bite some hard object. You can notice 

 the location of the strong muscles by which the mouth is shut. 

 as they swell in action. These are the muscles that a squirrel 



