THE MICROSCOPE AND INSECT LIFE 



the green fly, for it is used somewhat similarly, with 

 the difference that it sucks blood and not plant 

 juices. It may be well to mention here that the 

 females alone suck blood, but it is easy to distinguish 

 the sexes, for the antennae or feelers of the females 

 are thread-like whilst those of the males are 

 feathered. A few adult insects have no mouths, for 

 they never feed during their short lives. 



Caterpillars of all kinds and also beetles, grass- 

 hoppers, cockroaches and the like have biting- 

 mouth parts, and the student, who is not well versed 

 in insect anatomy, will learn more by watching one 

 of these insects partaking of a meal than by trying 

 to discover the uses of the various parts with the 

 aid of a microscope. Caterpillars as a rule are not 

 shy feeders, and a pocket lens will show their sickle- 

 like jaws in full play. The grubs of house-flies are 

 worth examining; they are soft and fleshy except 

 for a pair of horny hooks which are used to tear 

 up the food material. There are, however, so 

 many different mouths we cannot describe even the 

 typical ones, but the microscopist will soon dis- 

 cover those of special interest. 



The feet of insects do not show so much variation 

 as their mouths, nevertheless they will afford ample 

 material for many hours of study. Our butterfly, 

 which is now but a remnant, will provide our first 

 object. The design of its feet will depend, to some 

 extent, on the species of insect, but they will cer- 

 tainly be clawed. Other insects with clawed feet 

 — beetle^, bees, and wasps — may be examined, and 



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