[44]. A. S. Packard, Experiments on the vitality of insects, Psyche, ii, 17, 1877.
[45]. Waterhouse, Trans. Ent. Soc., London, 1889, p. xxiv.
[46]. J. Müller, Physiology of the Senses. Trans. by Baly, copied from Lubbock, p. 176.
[47]. Hauser here uses the word taster, but this means palpus or feeler. It is probably a lapsus pennæ for teeth (Kegeln).
[48]. In 1870 I observed these sense-pits in the antennæ and also in the cercopoda of the cockroach (Periplaneta americana). I counted about 90 pits on each cercus. They are much larger and much more numerous than similar pits in the antennæ of the same insect. I compared them to similar pits in the antennæ of the carrion-beetles, and argued that they were organs rather of the smelling than hearing. (Amer. Nat., iv., Dec. 1870.) Organs of smell in the flies (Chrysopila) and in the palpi, both labial and maxillary, of Perla were described in the same journal (Fig. 270). Compare Vom Rath’s account of the organs in the cercopods of Acheta (Fig. 271); also the singular organ discovered by him on the end of the palpus of butterflies, in which a number of hair-like rods (sh) are seated on branches of a common nerve (n, Fig. 272).
[49]. Forel, however (Recueil Zoologique Suisse, 1887), denies that these tympanic organs are necessarily ears, and thinks that all insects are deaf, with no special organs of hearing, but that sounds are heard by their tactile organs, just as deaf-mutes perceive at a distance the rumbling of a carriage. But he appears to overlook the fact that many Crustacea, and all shrimps and crabs, as well as many molluscs, have organs of hearing. The German anatomist Will believes that insects hear only the stridulation of their own species. Lubbock thinks that bees and ants are not deaf, but hear sounds so shrill as to be beyond our hearing.
[50]. Weismann, Die nachembryonale Entwicklung der Musciden. Zeitschr. für wissen. Zoologie, xiv, p. 196, 1864.
[51]. Plateau (1877) states that the digestive fluid of insects, as well as of Arachnids, Crustaceans, and Myriopods, has no analogy with the gastric juice of vertebrates; it rather resembles the pancreatic sugar of the higher animals. The acidity quite often observed is only very accessory in character, and not the sign of a physiological property. “Farther, I have found it in insects; Hoppe-Seyler has demonstrated in the Crustacea, and I have proved in the spiders, that the ferment causing the digestion of albuminoids is evidently quite different from the gastric pepsine of vertebrates; the addition of very feeble quantities of chlorhydric acid, far from promoting its action, retards or completely arrests it.” (Bull. Acad. roy. Belgique, 1877, p. 27.)
[52]. The word grès we translate as the layer of gum. Not sure of the English equivalent for grès, I applied to Dr. L. O. Howard, U. S. Entomologist, who kindly answers as follows: “I have consulted Mr. Philip Walker, a silk expert, who writes me the following paragraph: ‘Grès, as I understand it, is the gum of the silk fibre, hence the French name for raw silk, grèye, which is in distinction to the silk that has been boiled out in soap after twisting, or throwing, as it is called. As I understand it, the silk fibre is composed of the grès and fibroin. The former is soluble in alkali, like soap water, and the latter is not.’” While Blanc considers the grès as the product of a special secretion of the wall of the reservoir, Gilson regards its production as simultaneous with that of the silk or of the fibroin (l.c. 1893, p. 74).
[53]. On cytological differences in homologous organs. Report 63d meeting of British Assoc. Adv. Sc. for 1893. 1894. p. 913.