Very hind legs remaining, though the others have atrophied.1 little indeed is known as to these Insects. One of the most peculiar points of their economy appears to be that the galls giving rise to males are different from those producing females. Anoplura or Lice. ת Small Insects with thin integument; entirely wingless, the three thoracic segments indistinctly separated; the head bearing in front a short tube furnished with hooks; from which tube there can be protruded another very delicate suckingtube. Feet terminated by a single long claw. The Anoplura, Pediculidae, or lice are disgusting Insects about which but little is known. The most contrary opinions have been expressed as to their mode of taking their nourishment, which is, without exception, the blood of Mammals; on the bodies of which they pass the whole of their life. It is a most difficult matter to examine their mouth; the best information on this point is given by Schiödte and Graber, but though these two authorities agree, their results are very incomplete, and do not warrant us in expressing a confident opinion as to the nature of the relationship between Hemiptera and Anoplura a question that has been for long a moot one. The short tube furnished with hooks in front (Fig. 293, d) is considered to be the lower lip, and the tube inside is, it is suggested, a combination of FIG. 292.-Pediculus capithe homologues of maxillae and mandibles; there is also what may be a labrum (g); and inside the head a framework, at any rate analogous to if not homologous with, the parts of this kind we have described as existing in Hemiptera. All the parts, with the exception of the basal tube or head of the beak, are of the most minute and delicate nature, so that it is difficult to see their form or comprehend their relations. It is evident that they are very different anatomically from the mouth-parts of Hemiptera; still there is I tis, . Human head. (After Piaget.) 1 Rubsaamen's paper on these Insects gives references to most of the previous literature, Berlin, ent. Zeitschr. xxxix. 1894, p. 199. sufficient general resemblance to warrant the belief that the parts in the two may ultimately be shown to be also morphologically m. FIG. 293. Mouth organs of louse. (After Graber.) b, c, Chitinous envelope into which the beak can be withdrawn; d, head of the beak, with crown of spines; g, labrum; h, delicate tube protruded (very rarely seen in this state); m', unpaired muscle. similar. If Meinert be correct, this view will, however, not prove to have any foundation. He considers that morphologically the mouth of the louse has no similarity to that of the bug; the protrusible parts in the former he considers to be modifications of epipharynx and hypopharynx; and the rod-like structures to be hypopharyngeal lamellae; and that they are thus totally different from the setae of bugs.1 He considers Lice to be a distinct Order of Insects for which he proposes the name Siphunculata. The alimentary canal and nervous system resemble those of Mallophaga more than they do those of Hemiptera. The oesophagus leads into a large stomach bilobed in front; at the posterior extremity of this there open the four Malpighian tubes, and behind these there is a well-marked small intestine. The nervous system consists of a cephalic ganglion and of three other closely approximated ganglia, the posterior one the larger. It remains doubtful whether or not the first of these three ganglia is the infra-oesophageal one.2 The species of lice, so far as known, are not numerous, some six genera and about forty species being all that are recorded; they occur on various kinds of mammals, including some that live in water. Seals have a genus, Echinophthirius, peculiar to them. Monkeys are specially liable to be affected by lice; the genus that chiefly occurs on them is Pedicinus, a very distinct one, in which there are only three instead of five joints to the antennae. Perhaps the most remarkable louse is Haematomyzus elephantis, that of the elephant; it has a long proboscis in front of the head. As a rule each species of louse is confined to one species of Mammalia, or to very closely allied forms. Man is said to be infested 1 Ent. Meddel. iii. 1891, p. 82. 2 Cf. Graber, Zeitschr. wiss. Zool. xxii. 1872, p. 165, and Landois in the same Journal, xiv. 1864, p. 24. by three species, Pediculus capitis, P. vestimenti and Phthirius inguinalis; Meinert is of opinion that P. capitis and P. vestimenti are only one species, and Schiödte appears also to have thought this probable. Andrew Murray was of opinion that the heads of different varieties of men are infested by distinct varieties of P. capitis. His conclusion was chiefly based on examination of specimens preserved by Charles Darwin; it requires confirmation. Very little is known as to the life-history of the louse. Leeuwenhoek made himself the corpus vile for an experiment, from which he concluded that the Pediculus vestimenti is very prolific. That scientific men did not know whether the louse bites or sucks was formerly made the ground for a taunt. Schiödte has given an almost pleasing account of the way in which he settled this,' showing that the sucking action is beyond all doubt. Accounts of disease called Phthiriasis, attributed to lice, are to be found in many old books, but the evidence does not warrant us in believing anything more than that persons suffering from some disease, and in a neglected and filthy condition, were horribly infested with these disgusting Insects. It is usual to say that Pediculidae are Hemiptera degraded by a long exclusive persistence in parasitic habits. At present, however, this must be looked on as a pious opinion, rather than as an induction from our knowledge of their morphology and embryology; for this is at present too imperfect to warrant any final conclusion. 1 Ann. Nat. History (3), xvii. 1866, p. 213. NOTES AND CORRIGENDA VOL. VI. NOTE TO P. 4: Classification of Hymenoptera. Mr. W. Ashmead has published a sketch of a new classification of Hymenoptera, in which the points we have suggested are given effect to; the first division of the Petiolata being carried out with reference to the position of the ovipositor, while part of the Proctotrypidae is brought into the Aculeate division. We cannot, however, commend this arrangement as final, for several points have not received sufficient consideration. NOTE TO P. 172, line 22. For the words "We shall subsequently see," substitute "We have previously said " (p. 161). NOTE TO P. 350, line 10 from bottom: instead of "only one genus," read "only one Old World genus.” NOTE TO P. 541, line 16: instead of "two" read "ten." VOL. V. P. 217, line 4. For sterna read nota. P. 271. The lettering of Fig. 158 is erroneous; under the lower pointing line the letter d should be inserted, and the left hand upper pointing line should bear the letter c instead of d. P. 277, line 7. Instead of Fig. 162, read Fig. 163; and line 9, instead of Fig. 163 read Fig. 164. P. 378. The species figured has since been described by Mr. Haviland as Termes malayanus. P. 380. The species figured has since been described by Mr. Haviland as Termes mirabilis. P. 383. Hodotermes japonicus. 1869, p. 139) that this is not a earwig Brachylabis maritima. It has been recorded (P. Boston Soc. xii. Termite, but an immature form of the Pp. 480 and 481. It is not made clear that the distinction in the number of joints of the palpi of Phryganeides and Limnophilides applies to the males only; in both groups the number of joints in the females is five. The remark as to Phryganeides occurring in the Southern Hemisphere is erroneous. It is Limnophilides that reappear in Chili, not Phryganeides, P. 490. Fig. 333 A, ƒ and its line point to a division of the mesonotum, not of the metanotum. P. 564. Habits of Pelecinus. Mr. S. A. Forbes has recorded an observation suggesting that P. polyturator may be a parasite of Lamellicorn beetles of the genus Lachnosterna. See Rep. Ins. Illinois, xix. 1896, p. 79. 1 N. York Ent. Soc. vii. March 1899, p. 45. |