THE LIFE PROCESS IN INSECTS. 97 



garden, and orchard, popularly called worms, the great 

 majority are not worms at all, but the larvse of winged 

 insects. The student needs to be reminded here, that 

 little or nothing is known of the preparatory stages of 

 many of our native insects, and that in consequence 

 neither their place in nature, nor their importance to man, 

 can be rightly understood and appreciated. 



III. Voluntary Motion. The muscular system of in- 

 sects consists, for the most part, of isolated muscular 

 fibers, attached to prominences on the inside of its hollow, 

 chitiiious skeleton. Those fibers which move the body 

 segments are seen, upon dissection, arranged in whitish 

 bands along the sides of the body cavity. The strong 

 wing muscles fill the top of the thorax. Some of the 

 fibers that move the appendages of the body are attached 

 to tendons. 



The usual movable appendages of the insect body are 

 antennse, mouth parts, legs, and wings. The adaptations 

 of legs and wings to the habits of their possessors are not 

 less striking than those of mouth parts. Insects have 

 been studied which have legs adapted by their size, position, 

 and arrangement, for standing, for walking, for running, 

 for jumping, for swimming, and for seizing prey. The 

 most striking modifications of wings are the very common 

 ones already studied, the tegmina of Orthoptera, the 

 fore wings of many of the Hemiptera, and the halteres of 

 Diptera. 



But no account of muscles and motive organs will con- 

 vey any adequate notion of insect activity. This needs 

 to be seen to be appreciated ; and half an hour spent in 

 the open field on a warm afternoon, " amid hurrying 

 wings and scurrying feet," in careful observation of the 

 doings of these tiny creatures, will be of profit in learning 

 a few of the valuable lessons that cannot be put into 



NEED. ZOOL. 7 



