BUGS. 207 



osteolai" canal, and this is surrounded by a more or less rugged and granulated space, the 

 evaporating surface. The secretion is an ethereal oil variously combined, speedily dis- 

 sipated in the atmosphere, and often having an odor similar to that of pears or other 

 fruit. In some species of Coreidfe it is decidedly aromatic, and in a few it has a si^icy 

 smell very much like that of cinnamon. 



These organs appear to be absent from the Homoptera ; but most Cicadas secrete a 

 powdery substance, scales, or hairy patches from the underside of the body, while the 

 Fulgoridse become covered beneath and on the end of the abdomen with a cottony or 

 fibrous white substance. Some of the Coccidse secrete wax or lac, and others various kinds 

 of valuable dyes. The functions of nutrition are performed by a well-defined system 

 of organs, of various forms, and often of remarkable complexity. Behind the mouth a 

 short, distinct throat receives the fluid from two pairs of ducts connected with the 

 salivary glands. From this the stomach is continued by an intestine-like tube, swollen 

 in two or more places, until it reaches the vent. The first stomach, or gizzard, is a 

 large, straight, frequently constricted glandular sac, narrowed behind into a long, 

 flexed or convoluted canal (duodenum), also glandular, and dilated posterioi-ly into the 

 chylific stomach; this is often continued backwards as a slender intestine (ilium), 

 emptying into a colon-like expansion that terminates with the correspondingly wide 

 rectum. Both of the intestinal parts of this organism are sometimes reduced to mere 

 peduncles of the three pouched dilatations. 



In the Cicadas, Tettigonids, and Cercopis the first stomach is bent into a loop, and 

 the duodenal portion runs off slender in convolutions and re-enters the stomach next the 

 loojJ, the loop itself being attached to the oesophagus by a bundle of ligaments. Tlie 

 iliac portion, also long and convoluted, is attached to the other side of the loop and 

 then runs backwards as usual. 



The ovarian tubes vary greatly in number, and range from two to fifty or more in 

 each aggregation, according to the species. In the same genus a wide disparity in the 

 number of these organs frequently occurs. A large proportion of the Heteroptera 

 possess five to seven ; while the Cicadas have fifty to sixty, gathered into two large, 

 rounded bundles ; the Psyllidse acquire about thirty, and the Coccidrs an almost un- 

 limited number. In the latter they are arranged in two stellate 

 branches. 



Most of the eggs of the higher Heteroptera are ornamented 

 with bands, or other patterns of color, and many of them are 

 fluted, beaded, ribbed, etc. These also ai-e capped by a toothed 

 and movable lid, provided with a ligamentous sprina; to aid the 



' L o 1 o FiC 2R7 "FpffS of 



emergence of the larva. The number of egars laid by a single simchia, natural 



f . , , . , , . , . , .,. size and enlarged. 



female varies also, not only with the species, but m the indi- 

 viduals. Some have been known to lay as few as twenty-five eggs, while the female 

 Cicada sometimes deposits more than five hundred. 



A well-developed nervous system appears in the adults, in general approaching that 

 of the Coleoptera, being much concentrated towards the head in the principal groups. 

 This is especially the case in the higher Heteroptera, where the cephalic ganglion or 

 brain is massive, closely connected with the suboesophagial ganglion by two stout cords 

 which pass below the gullet, and this in turn is immediately followed by the great 

 thoracic ganglia, all three of these being fused together and continued some distance 

 backward by a great nervous trunk. The brain often consists of a pair of distinct 

 lobes, from which two heavy branches pass off to the eyes, more slender ones to the 



