8 HOW TO USE THIS BOOK 



be left over to replace those that are spoiled during the work. 

 In a few of the lessons one or two specimens placed where the 

 pupils can examine them will be sufficient. Have each pupil 

 bring his own specimen if possible; otherwise have a few 

 volunteers bring enough for the whole room. 



If it is planned to preserve specimens, those that can not be 

 dried may be kept in the following mixture : 



Formalin, one ounce. 

 Water, one quart. 



This is a safe, reliable, and inexpensive mixture, and preserves 

 both vegetable and animal tissues in nearly their natural 

 colors. Insects may be painlessly killed by putting them in 

 a tightly closed fruit jar containing a few drops of chloro- 

 form. 



Kindness to Animals. When live insects or animals are 

 kept in the schoolroom the teacher should exercise the greatest 

 care for their comfort, and should set them free as soon as 

 possible, as an example of kindness to animals. While some 

 may die because they have reached maturity, there can be no 

 excuse for allowing any to die from neglect. 



Devices. Before giving a lesson the teacher should do the 

 drawing and composition work in order to know what work to 

 expect from the pupils, and what difficulties they will be likely 

 to encounter. 



It is often possible to appeal to an indifferent pupil by ask- 

 ing him to get a specimen that is difficult to obtain. The boy 

 at the foot of the class often leads it in knowledge of the woods 

 and fields and brooks. 



A fruitful source of specimens is the walk to and from 

 school. Go home with the pupils and show them the wealth 

 of material at their doors. Occasionally take the pupils out 

 for an informal walk or ride to search for specimens, and to 

 observe things growing in their natural homes. 



Have growing specimens of plants and animals in the school- 



