208 



THYSANOURA. PODURID^E. 



In the PODURID.E, the appendages to the sides of the abdomen 

 are wanting ; but the extremity of it is prolonged into a forked 

 tail, by which these insects can execute very surprising leaps. 



This, when not in action, is bent 

 forwards beneath the abdomen ; 

 and it is by the sudden ex- 

 tension of it, that the leap is 

 produced, 

 formation, 

 commonly 



FIG. 434. PODURA. 



name 



scales with which their bodies are 

 great interest to the Microscopist ; 



From this con- 

 the Poduras are 

 known under the 

 of Spring - tails. The 

 covered, are objects of 

 for they have a most 



elaborate and minute structure, which can only be made out by 

 instruments of the best quality ; hence they are very valuable 

 test objects. 



