140 



BEES AND BEE-KEEPING. 



alarum muscles, which moves the membranous exten- 

 sion lying behind it constituting the wing. 



A simple experiment, which I would recommend 

 all my readers to try, and which I have often used 

 as an illustration, will make clear at once how this 

 arrangement wafts the insect forwards ; but we 

 must be careful to remember, in interpreting it, that 

 the wings in flying are not carried over the back, 

 but are brought round, with their length approxi- 

 mately at right angles to that of the body, so 

 that the costal nervure goes first, and is followed 

 by the membrane. Gum or glue the edge of a 



Fig. 28.— Experiment on Wing Action. 

 pw, Paper Wing ; s, SticK ; DS, Down Stroke ; US, Up Stroke ; c, c, c, Air Currents. 



piece of writing-paper, 3m. or 4m. wide, along 

 the stick of a penholder, or some such form, so 

 that the paper represents the wing-membrane, and 

 the stick the costal nervure. Now place two 

 lighted candles as in Fig. 28, and wave the paper 

 up and down between them, so holding the stick 

 that while it is at rest the paper is horizontal. 

 Both flames will immediately indicate a current from 



