METHOD OF STUDYING MATERIAL. 217 



studying the structure of the crayfish, for instance (see 

 Fig. 23), if the children want to talk about its great 

 "pinchers " first, let them do so, but not until they have 

 studied the body and its divisions, and located the 

 " pinchers " with reference to the body. From the 

 " pinchers " they will naturally pass to the legs, and 

 then to the swimmerets and tail fin, the parts by means 

 of which the animal moves. Later can come eyes or 

 feelers, large and small ; the order is not material. 

 The mouth parts, which are very difficult to see, and at 

 best will not be understood, should be left to the last. 

 If they begin the study of appendages with the large 

 feelers or antennae, take up next the small feelers most 

 closely related to them. In studying the pea flower, 

 if they are particularly interested in the little pod 

 developing in the flower, it may be best to study this 

 first, and consider the other parts in their relation to 

 pod, to investigate the way in which they are formed 

 so as to produce and protect the pod. We may then 

 add another rule, subordinate to the others, which may 

 influence the order in studying structure. 



Fourth. Study first and emphasize those parts or 

 properties in which the children are most interested, and 

 which they can see best, and leave to the last what is 

 most difficult to see or understand. We may find it 

 best in studying limestone to begin with its efferves- 

 cence with acid, or in studying mica to begin with its 

 cleavage, or tendency to split into thin plates. These 

 greatly interest the children. 



What has been said about testing the order, clearness^ 



