The organs are generally restricted to certain joints of the antennae, e.g third joint in Diptera Brachycera, terminal joints in Lepidoptera Rhopalocera Hauser points out that the number and perfection of the organs are in correlation with the habits of the insects examined: The Syrphidae (Diptera Brachycera) with larvae feeding on vegetable food, etc, have but few (one to four); those with larvae feeding on dung have many; the Honey-bee has 14,000 to 15,000 grooves and 300 cones on one antenna, Ichneumon 3000 grooves: but in the phytophagous subsection of the Hymenoptera grooves are absent, and cones are present in comparatively small numbers. The Lamellicorn beetles have vast numbers on the foliate expansions of the joints, e.g. male Cockchafer about 39,000, female 35,000. Hauser was unable to find any organs in the antennae of Hemiptera and Neuroptera (Chrysopa), nor in the Carabidae, but in the latter and in other Coleoptera he found identical structures on the maxillary and labial palpi. They may, however, in these situations have a gustatory rather than an olfactory function. Cones especially appear to be present in larvae, not only on the antennae, but also on the palpi.

In many instances, however, the organs appear to be absent.

Cone-like structures occur on the antennae of Lithobius forficatus and Julus terrestris among Myriopoda; see also Bourne (G. C.) on Sphaerotherium, J. L. S. xix. Dec. 1885.

Insecta, MacLachlan, Encyclopaedia Britannica (ed. ix.) xiii. Anatomia degli Insetti, Camerano, Turin, 1882. Die Insekten, Graber, 'Naturkrafte' series, xx., Munich, 1877. Elementary Text-book of Entomology, W. F. Kirby, 1885. Intro-duction to Entomology, Kirby and Spence, 4 vols. (vols. iii. and iv. 1826, which contain orismology and anatomy, have never been reprinted). Guide to the study of Insects, Packard (ed. 3), Salem, 1872. Modern Classification of Insecta, Westwood, 2 vols., London, 1839. Entomologists Text-book, Idem, 1838.

Orthoptera. Orth.Europaea, Fischer, Leipzig, 1853; see for Family Blattinae, pp. 84-88. Recherches anatomiques, etc., sur les Orthopteres, Leon Dufour, Memoires, etc., des savants Etrangers, Acad. Roy. de France, 1841. Classification of Orthoptera and Neuroptera, and Genealogy of Insects, Packard, American Naturalist, xvii. 1883.

The Cockroach.Beitrage zur naheren Kentniss von Periplaneta orientalis, Cornelius, Elberfeld, 1853; cf. Hagen, Stettin. Entomol. Zeitung, xv. 1854, p. 378; and Huxley, Anatomy of Invertebrated Animals, 1877, p. 398.

Structure, movement, and function of Insectan limbs. Dahl, A. N. 50, 1884. Adhesive organs. Simmermacher, Z. W. Z. xl. 1884; cf. Dewitz, Z. A. vii. 1884; viii. .1885; and Reviews by Emery and Graber in Biol. Centralbl. iv. 1884-85. Glands of feet. Dahl, A. M. A. xxv. 1885.

Folding of wings.Scudder, American Naturalist, x. 1876; De Saussure, A. Sc. N. (5) x. 1868. Circulation in wings of Blatta, Moseley, Q. J. M. xi. 1871.

Thoracic muscles.Luks, J. Z. xvi. 1883; Structure of muscle. von Limbeck, SB. Akad. Wien, xci. Abth. 3, 1885.

Somites of head.Packard, American Naturalist, xvii. 1883.

Structure of antennae, Hauser, Z. W. Z. xxxiv. 1880. Mouth-parts of Insecta. Brulle, A. Sc. N. (3), ii. 1844; Chatin, A. N. H. (5), xiv. 1884.

Brain of Cockroach.Newton, Q. J. M. xix. 1879. Of Locust. Packard, American Naturalist, xv. 1881. Stoma togas trie and sympathetic systems. Kostler, Z. W. Z. xxxix. 1883. Nervous system of Insects in general. Leydig, Vom Bau des Thierischen Korpers, Tubingen, i. 1864 and Atlas. Lobi olfactorii, Flogel, Z. A. vi. 1883, p. 539; Id. Z. W. Z. xxx. (Suppl.) 1878, described under Blatta, p. 566.

Digestive tract, etc. Basch, SB. Akad.Wien, xxxiii. 1858. Salivary glands. Kupfer, Festgabe zur Karl Ludwig, 1874. Gizzard of Orthoptera. Wilde, A. N. 43, 1877. Appendices pyloricae. Graber, SB. Akad. Wien, lix. Abth. i. 1869. Rectum. Chun, Abhandl. Senck. Gesellsch. x. 1875.

Malpighian tubes.Schindler, Z. W. Z. xxx. 1878.

Corpus adiposum.Targione Tozzetti, Bolletino della Soc. Entomol. Ital. iii. 1871; iv. 1872. Its formation in Corethra. Wielowicjski, Z. A. vi. 1883.

Heart.Graber, A. M. A. ix. 1873. Ventral pulsatile sinus. Id. op. cit. xii. 1876. Blood corpuscles. Id. SB. Akad. Wien, lxiv. Abth. i. 1871. Cf. on heart. Poletajewa, Z. A. ix. 1886.

Stigmata.Krancher, Z. W. Z. xxxv. 1880; Landois and Thelen, Ibid. xvii. 1877 (for P. orientalis, see Taf. xii. fig. 12). Primary number in Insecta. Packard, American Naturalist, viii. 1874. Tracheal System of Insecta. Palmen, Morphologie des Tracheensystems, Leipzig, 1877. Minute Anatomy of Tracheae. Macloskie, American Naturalist, xviii. 1884.

Testes of Periplaneta.Rajewski in Hoffman and Schwalbe, Jahresbericht fur Anat. und Phys. 1875, p. 425. Male genital armature of same. Huxley, Anatomy of Invertebrated Animals, 1877, p. 406.

Female organs, etc. see end of description of Pl. viii.

Histology, Histolysis, and Histogenesis of Insecta, Viallanes, A. Sc. N. (6), xiv. 1882. Cf. Ludwig, Untersuchungen zur Anat, etc. der Thiere, Bonn, 1883, passim.

Development of Blatta germanica. Rathke, Meckel's Archiv (Arch, fur Anat. und Physiol.), 1832. Cf. A Note on same. Patten, Q. J. M. xxiv. 1884.