. Elementary entomology . Fig. 43. Nervous system of head of cockroach a, antenna! nerve ; ag, anterior lateral ganglion of sympathetic system ; /', brain ; d, salivary duct; /, frontal ganglion ; h, hypopharj'nx ; /, labrum ; //, labium ; ;«, mandibular nerve ; mx, maxillary nerve ; «/, nerve to labrum ; «//, nerve to labium ; 0, optic nerve ; oc, esophageal commissure; oe, esophagus; pg, posterior lateral ganglion of sympathetic system ; ;-, recurrent nerve of sympathetic system; s, subesophageal ganglion. (After Hofer, from Folsom) forming a nerve center for its segment. Thus a decapitated
. Elementary entomology . Fig. 43. Nervous system of head of cockroach a, antenna! nerve ; ag, anterior lateral ganglion of sympathetic system ; /', brain ; d, salivary duct; /, frontal ganglion ; h, hypopharj'nx ; /, labrum ; //, labium ; ;«, mandibular nerve ; mx, maxillary nerve ; «/, nerve to labrum ; «//, nerve to labium ; 0, optic nerve ; oc, esophageal commissure; oe, esophagus; pg, posterior lateral ganglion of sympathetic system ; ;-, recurrent nerve of sympathetic system; s, subesophageal ganglion. (After Hofer, from Folsom) forming a nerve center for its segment. Thus a decapitated insect will walk or fl)', and the abdomen of a grasshopper will continue to breathe, these functions being controlled by the seg- mental ganglia, though lacking coordination. In addition to the main nervous system there is a sympathetic system, one part of which runs along the upper part of the alimentary canal and con- trols the digestive process, while a small ventral sympathetic nerve gives off branches which control the spiracle muscles. Dr. J. B. Smith, in his "" Economic Entomology," gives an interesting account of some experiments which show the relation of the brain and ganglia to the body :
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Keywords: ., bookcentury1900, bookdecade1, booksubjectentomology, bookyear1912
