246 TEXT-BOOK OF ENTOMOLOGY 



which either pervades the whole body or only the appendages 

 innervated by the injured ganglion. 



7. As a result of an injury to the brain there is such a lack of 

 steadiness in the movements that the insect walks or flies in a circle ; 

 for instance, a fly or dragon-fly thus injured in flying describes a 

 circle or spiral. Steiner, in making this experiment, observed that 

 the insect circled on its uninjured side. The brain is thus a motor 

 centre. 



8. By injuring a thoracic ganglion, one or all the organs which 

 receive nerves from the ganglion are momentarily weakened. After- 

 wards the functions become restored. Sometimes, however, the 

 insect walks in a circle. Faivre observed that after the destruction 

 of the metathoracic ganglion of Dytieus marginal is the hind wings 

 and hind legs were partially paralyzed (Kolbe, ex Yersin). 



LITERATURE ON THE NERVOUS SYSTEM 

 a. General 



Newport, George. On the nervous system of the Sphinx Ugitstri L., and on the 



changes which it undergoes during a part of the metamorphoses of the insect. 



(Phil. Trans. Roy. Soc., London, 1832, pp. 383-398 ; 1834, pp. 389-423, Pis.) 

 Helmholtz, H. L. F. De fabrica systematis nervosi evertebratorum. Diss. in 



aug. Berolini, 1842. 

 Blanchard, E. Kecherches anatomiques et zoologiques sur le systeme nerveux des 



animaux sans vertebres. Du systeme nerveux des insectes. (Annales des 



Sciences nat., Se'r. 3, v, 1846, pp. 273-379, 8 Pis.) 



Du systeme nerveux chez les invertebres dans ses rapports avec la classifi- 

 cation de ces animaux. Paris, 1849. 



in Cuvier's Regne animal. (Edition accompagne'e de planches grave'es. 



Insectes. PI. 3, 3a, and 4.) 



Leidy, Joseph. History and anatomy of the hemipterous genus Belostoma. 



(Memoirs Amer. Acad. Arts and Sc., N. S. iv, 1849, pp. 57-67, 1 PL) 

 Scheiber, S. H. Vergleichende Anatomie und Physiologic der (Estridenlarven. 



(Sitzungsb. k. Akad. wiss. Wien. Math.-Naturwiss. Cl., xli, 1860, pp. 439- 



496 ; xlv, 1862, pp. 7-68 ; 5 Taf.) 

 Tullberg, Tycho. Sveriges Podurider. K. Svenska vet. Akad. Handl. x, 1872, 



pp. 1-70, 12 Taf.) 

 Berlese, A. Osservazione sulla anatomia descrittiva del Grylhis campestris L. 



(Atti della soc. Veneto-Trentina, 1880, vii, pp. 200-299.) 

 Baudelot, E. Contributions a la physiologic der systeme nerveux des insectes. 



(Revue d. sc. nat., i, pp. 2(19-280, 1872.) 

 Studer, Th. Ueber Nervenendiguug bei Insekten. Kleine Beitrage zur Histolo- 



gie der Insekten. (Mitt. Naturf. Ges., Bern, 1874, pp. 97-104, 1 Taf.) 

 Brandt, E. Recherches anatoiniquf-s et morphologiques sur le systeme nerveux 



des insectes Hyme'nopteres. (Compt. rendus de 1'Acad. Sc., Paris, 1875.) 



Ueber das Nervensystem der Apiden. (Sitzungsb. d. naturf. Ges., in 



Petersbourg, vii, 1876.) 



Ueber das Nervensystem der Schmetterlingsraupen. (Verhandl. derRuss. 



