264 FUNDAMENTALS OF AGRICULTURE. 



others are long and threadlike, others are like a 

 feather, others are like a string of beads, while others 

 are of various shapes. 



How Insects Breathe. Strange to say an insect has 

 no nose, and does not breathe through its mouth at 



Ventral transverse trachea 



Dorsal ^ongliudinal 



trachea 



Lateral longitudinal trachea 



BREATHING TUBES OF GRASSHOPPER (HERRICK's ZOOLOGY). 



all. The air enters an insect's body through holes 

 along the sides of the abdomen and thorax, and passes 

 into a system of tiny tubes that run all through the 

 body, similar to the blood vessels of a higher animal. 

 These tubes divide and subdivide into smaller and 

 smaller branches that reach every part of the body, 

 even entering the legs and wings to some extent. 



How Insects Grow. The mother grasshopper, in 

 the fall, makes a hole, with the end of her abdomen, 

 in the ground, and in this lays her eggs, several dozen, 

 in a sort of capsule or pod, where they remain until the 

 following spring, when they hatch and the young grass- 

 hoppers appear. The young as soon as they come 

 from the egg may be recognized as grasshoppers. 

 They are called nymphs. They eat greedily and grow 

 very fast, becoming full-grown in about two months. 

 During this time they molt or shed their skins several 

 times. The skin of a young grasshopper gets hard 

 and soon becomes too small, because it will not stretch, 

 and has to be shed for a new and larger skin. Every 

 shedding of the skin represents a step in the growth 

 and size of the young grasshopper. After the first 

 molt or two the wings appear as small backward-pro- 



