INSECTS 



807 



of many small eyes, from 50 in some ants to many thou- 

 sands in a butterfly or dragon-fly. Between these oom- 

 pcmnd eyes, from one to four simple eyes are to be found 



1138. Nymphs of l.ii four-lined liaf-bue a..d adult of 

 the tdrnished plant-bug. 



Tlie smallest one is tlie nymph recently hatched. The next 

 is the nvmph after the lir.st moult. The imago is 

 shown at the right. Hair lines at the right of nymphs, 

 and small figure near imago indicate the natural size. 



in many adult Insects. Caterpillars and other larvae pos- 

 sess only simple eyes. .It is thought that each facet of the 

 compound eye sees a part of an object; thus the whole 

 eye would form a mosaic picture on the Insect's brain. 

 The simple eyes doubtless see as our eyes do, and seem 

 to be best adapted for use in dark places and for near 

 vision. Insects do not see the form of objects distinctly, 

 but their eyes are doubtless superior to ours in distin- 

 guishing the smallest 

 movements of an ob- 

 ject. It is now supposed 

 that no Insects can dis- 

 tinctly see objects at a 

 greater distance than 

 feet. It must be a 



I Its 





back to its home. In- 

 sects are doubtless 

 able to distinguish the 

 color of objects, and 

 some Insects seem to prefer certain colors. Blue is said 

 to be the favorite color of tlie honey-bee, and violet that 

 of ants; ants are also apparently sensitive to the ultra- 

 violet rays of light, which man cannot perceive. It is 

 generally supposed that the shape and high colors of 

 flowers attract Insects: but recent ex- 

 periments seem to show that Insects 

 are guided to flowers by the sense of 

 smell rather than by sight. 



The hard outer skin of an Insect 



has no nerves distributed in it, hence 



t IS not sensitive; but it is pierced 



vith holes, in which grow hairs that 



ire in connection with nerves at their 



base. It is by means of these sensory 



that Insects feel, and are sensi- 



to touch on most parts of the 



body. 



s Insects are 



ui-ally follow that they 

 have ears to hear, for 

 there is every reason to 

 suppose that they make 

 these souu.is as love- 



1140. Tent-caterpi 



A maggot.. 



, dipterous insect. 



bees and ants hear sounds too shrill for our ears. In- 

 sects have no true voice, but produce various noises me- 

 chanically, either by rapid movements of their wings, 

 which causes the humming of bees and flies, or by fric- 

 tion between roughened surfaces on the body or its ap- 

 pendages, thus producing the rasping sounds or shrill 

 cries of some crickets and grasshoppers. The house-fly 

 hums on F, thus vibrating its 

 wings 335 times in a second, 

 while the wing tone of the 

 honey-bee is A. Usually the 

 males are the musicians t.f tin- 

 Insect world, but it is th. I'. 

 male of the familiar nn'sijuiio 

 which does the singing, iind 

 the "biting" also. The male 

 mosquito doubtless hears the 

 song of his mate by means of 

 his antennee, as the song 

 causes the antennal hairs to 

 vibrate rapidly. Organs which 



are 



ike 



been found in various parts 

 of the body of Insects. The 

 common brown grassliop|i.i-< ..f i 

 ear on each side of tli<- tii'^t -..l 

 one can easily distingni.^h will: i 

 brane or tympanum stn'ili.,1 .. 

 the long-horned .grc-ii l^li^-Im 



front V-x. 's.,iii.- Iliiiik Ihai iiP.-M 



of the |,r,v,i.liM,i .if 111.. .Iiivnio, 



Many of 

 ds and 



faculty 

 • highly 



Insects undoubtedly possess the sense of taste. When 

 morphine or strychnine was mixed wdth honey, ants 

 perceived the fraud the moment they began to feed. 

 The substitution of alum for sugar was soon detected 

 by wasps. Bees and wasps seem to have a more delicate 

 gustatory sense than flies. Tasteorgans have been 

 found in many Insects, and are usually situated 

 either in the mouth or on the organs immediately 

 surrounding it. 



Many experiments have shown that the e 

 are the principal organs of smell in Insects. 

 Blow-flies and cockroaches which have had their 

 antennsB removed are not attracted by their fa- 

 vorite food, and male Insects find 

 their mates with difUculty when 

 deprived of their antennse. /y \j 



The familiar world which sur- 

 rounds us may be a totally differ- 

 ent place to Insects. To them it 

 may be full of music 

 which we cannot 

 hear, of color which 



ith 



ii4j Cocoon of pro- 

 methea moth. 

 Made m the roll of a leaf. 

 The msec t we a e<i a web 

 about the le it stalk and 

 ties It to the parent 

 stem so that the leaf 

 cannot fall 



powers. 



'Bxeir Number, Slr.e iiiiil ^ii/e. -Experts guess that 

 there are from 2,000,000 to 10,000,000 different kinds 

 of Insects in the world. Only about 400,000 of these 

 have yet been described and named by man. Between 

 30,000 and 40,000 are now known in North America. 

 Four-fifths of all the kinds of animals are Insects ; some 

 single families of Insects are said to contain more spe- 

 cies than one can see stars in a clear sky at night; and 



