THE STRUCTURE AND LIFE OF INSECTS 241 



XLV. A SCHOOL-COURSE ON THE STRUC- 

 TURE AND LIFE OF INSECTS. 



METHODS OF DISPLAYING INSECT STRUCTURES 

 TO MANY PEOPLE AT ONCE. 



I wish to supply hints for a short school-course on 

 insects. Besides supplying information on insects as a 

 class, I propose to show how the structure of an insect 

 can be made evident to a number of pupils at once, and 

 this is the difficult part of my enterprise. The methods 

 which I recommend will, I know, seem too laborious to 

 most teachers. Yet they have all been carried out suc- 

 cessfully in my own class-room, and I see no reason why 

 they should not be practised in some of the better-equipped 

 schools. An oxy-hydrogen, or better still, an electric 

 lantern, is required. The teacher should be practised 

 in the simpler methods of demonstrating and mounting 

 insect-structures. The life-histories of a few common 

 insects should also be rendered familiar by rearing the 

 insects in breeding-cages. I do not recommend this 

 subject to all teachers, nor to all amateur naturalists. 

 Some knowledge, skill and experience are called for, and 

 the study is better suited to a small class of elder pupils 

 than to a large class of beginners. 



Many of the characteristic features of an insect can be 

 seen by the naked eye or a lens of low power, but this 

 is not quite enough. It is sometimes indispensable to 

 examine minute parts, such as jaws or air- tubes. We have 

 found it a simple matter to fit a low microscope objective 

 (2 in. or i in.) to the lantern, and this makes it possible 

 to show to a whole class at once every detail which is 

 likely to be profitable to young students. We may, I 

 think, anticipate that the facilities which the optical 

 lantern affords will soon be more widely turned to account, 

 and that the higher elementary schools at least will before 



Q 



