144 Zoology of Colorado 



sent only a small part of our debt to the insect world. In recent 

 years, the science of heredity has been made over by intensive 

 study of a minute red-eyed fly which breeds in over-ripe fruit, 

 the Drosophila. Many insects are beautiful, and charm us as 

 do the flowers; many others have interesting habits, which Fabre, 

 Peckham, Wheeler, Rau and others have taught us how to ob- 

 serve. The amateur naturalist finds among the insects materials 

 for his collections, and opportunities for the discovery of entirely 

 new facts. With the increasing development of ultra-technical 

 methods, and the use of costly apparatus, we are shut off in a 

 great measure from participating in the advancement of science. 

 It is somewhat as if all musical instruments were abolished except 

 the pipe-organ, all singing except that in grand opera. It would 

 be a serious social loss, tending to lower the level of intelligence 

 were these conditions universal. But happily it is not so with 

 the insects. The necessary outfit costs only a few dollars, and 

 takes little space. The species of North American insects will 

 not be all catalogued for a very long time to come, and the possible 

 studies of their life histories are almost infinite. Occasionally 

 the observer will be rewarded by an important discovery, per- 

 haps of great practical value; but at the very least he will gain 

 much pleasure and the consciousness of personal development. 



Apterygota 



The most simple or primitive insects are those which have 

 no wings, and show no signs of having had winged ancestors. 

 The flea, bed-bug and the louse are all believed to have come 

 from winged groups, but this is not true of the Thysanura, Protura 

 and Collembola. The Thysanura, called Bristle-tails or Silver- 

 fish, are long carrot-shaped animals of no great size, often found 

 under stones. There are usually three tails, and the antennae 

 are long. The Collembola, also common under stones, are called 

 Spring-tails, from their habit of leaping by the sudden extension 

 of the furcula beneath the tail. In some, however, this furcula 

 is wanting. They are all very small and the antennae are not 

 very long, being usually four-jointed. Our species have received 

 hardly any attention, and no doubt many discoveries await a 

 keen collector. The Protura, very small elongated insects without 



