The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . 2.—Head and Prothorax of Cicad, parts separated. I., a, frons; 6, clypeus; c, labrum; d, , Same from , , 1st maxilla; a, base; 6, sheath; c, stylet; c, , 2nd maxillae, a, sub-mentum; b, mcntum; c, ligula, formingbeak; d, hypopharynx (shown also from front d, andbehind d).v., Prothorax, 6, haunch; o, trochanter. sub-oraers, but an interesting peculiarity of the Hemipterais the occasional presence of winged and wingless races of thesame species. Eleven a
The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . 2.—Head and Prothorax of Cicad, parts separated. I., a, frons; 6, clypeus; c, labrum; d, , Same from , , 1st maxilla; a, base; 6, sheath; c, stylet; c, , 2nd maxillae, a, sub-mentum; b, mcntum; c, ligula, formingbeak; d, hypopharynx (shown also from front d, andbehind d).v., Prothorax, 6, haunch; o, trochanter. sub-oraers, but an interesting peculiarity of the Hemipterais the occasional presence of winged and wingless races of thesame species. Eleven abdominal segments can be recognized,at least in the early stages; as the adult condition is reached,the hinder segments become reduced or modified in connexionwith the external reproductive organs, and show, in some maleHemiptera, a marked asymmetry. The typical insectan ovi-positor with its three pairs of processes, one pair belonging to theeighth and two pairs to the ninth abdominal segment, can bedistinguished in the the nervous system the concentration of the trunk ganglia. TERZI~ At(cr Mjrlall, Bull. 4 () Dtv. Enl VS. Vtpl. Agr. Fig. ^, Cast-off iiymphal skin of Bed-bug (.Cimex leclularius);b. Second instar after emergence from a; c, The same after a meal. into a single nerve-centre situated in the thorax is digestive system has a slender gullet, a large crop and nogizzard; in some Hemiptera the hinder region of the mid-gutforms a twisted loop with the gullet. Usually there are fourexcretory (Malpighian) tubes; but there are only two in theCoccidae and none in the Aphidae. Stink glands, whichsecrete a nauseous fluid with a defensive function, are present
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectencyclo, bookyear1910
