KANE] NATURE-STUDY IN MILWAUKEE AND VICINITY 9 



Can a crayfish hear? If so, where are its ears? 

 Can a crayfish smell? If it can, find its nose. 



I did not expect my pupils to answer either of these questions. 

 I like to give them occasional ones that I know they cannot answer, 

 just to set them to thinking. But to my surprise, several pupils 

 insisted that the little white spots at the base of the antenules 

 were its ears. I pondered for some time over the way in which 

 they got the information. There was no book at their command, 

 and I thought it hardly possible any one could have told them. I 

 afterwards discovered that they had arrived at their conclusion in 

 this way: It could hear; that was evident from its behavior. 

 There were no ears in the place where ears were supposed to be. 

 They had come upon the little white spots at the base of the 

 antenules when they were studying the animal ; and remembering 

 a lesson they had had last fall on the grasshopper when on each 

 front leg on each knee joint was found a roundish spot which 

 proved to be an ear, they decided that if grasshoppers could have 

 their ears on their knee joints, crayfish might have them at the 

 base of their feelers. They could find nothing that looked like a 

 nose ; so they decided that the sense of smell lay in the antennae by 

 the way the animal used them when walking and when examining 

 its food. They also brought their knowledge of ants' sense of smell 

 to their assistance in the solution of this problem. 



A question requiring a thoughtful answer may often be given 

 incidentally without any great preparation on the part of the 

 teacher. For example, in the spring the children come with pussy- 

 willow twigs which I place in water so that the emergence of the 

 blossoms from the furry coats may be seen. It is a great surprise 

 to the children to learn that willows, elms, and maples have blos- 

 soms. The flowers, being comparatively inconspicuous, have 

 escaped their observation. I ask them, "Which appears first on a 

 plant in the spring — leaves or blossoms?" They answer leaves, of 

 course, and reference is generally made to the apple tree. But we 

 turn to our pussies in the window that are yellow with pollen when 

 not a green leaf is in sight. Here is an apparent inconsistency; 

 but they have learned by experience that there is no such thing as a 

 freak in nature, that there is some reason for every deviation from 

 the beaten path. I ask them to watch the blossoming of various 

 trees and to let me know some day why the apple tree sends out its 



