4
( clv ) glands, though possibly they might secrete soniething of a 1nucilaginou3 nature that gives coherence to the froth. He hoped some of the Fellowa present would take the oppor- tunity to make observations on the insect with a view to confirming or disproving the account he had just given. [Since the date of this meeting, I have found that a full account, agreeing in all essential respects with my own observalion~, wag given by Dr. Karel Sulc in &it. fiir Wissen. Zool. Bd. 99, pp. 147 et sep. (Nov. 1911).-C. J. G.] HanrILTori DRUCE exhibhd about 30 specimens of Hemw is tityus (bornbylijormis) and H. fuciforniis, which he had taken near Brockenhurst on itby 18th, 19th, 20th, and remarked that the extensive wood cutting in the Forest had not depleted their numbers. Papers. BOTH SPECIES OF HEMARIS FROM THE NEW FOREsT.--&h. The following Papers were read :- ‘I Studies in Rhyncophora, iv; a preliminary note on the Male Genitalia,” by DAl71~ SHARP, lf.A., M.B., F.R.S., etc. ‘. Notes on the Ontogeny and Morphology of the Male Genital Tube in Coleoptera,” by FREDERICK MUIR, F.E.S. Notes on various Species of the American Genus Astylus, Cast. (Coleoptera), with Descriptions of their Sexual Charac- ters,” by G. C. CHAMPION, A.L.S., F.Z.S. .‘ New Staphylinidae from Singapore, pt. ii,” by NALCOLM CANERON, M.B., R.N. Wednesday, October Ind, 1918, Dr. C. J. GAHAN, KA., D.Sc., President, in the Chair. Alteration of Bye-law. The proposed alteration in Bye-law viii mas read for the second time. Exh ibitiorbs. LIFE-HISTORY OF LYCAENA .ucoN.-Dr. CHAPMAN exhibited a bred specimen of Lycuelaa alcorb, probably the first specimea .

Wednesday, October 2nd, 1918

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Page 1: Wednesday, October 2nd, 1918

( clv )

glands, though possibly they might secrete soniething of a 1nucilaginou3 nature that gives coherence to the froth. He hoped some of the Fellowa present would take the oppor- tunity to make observations on the insect with a view to confirming or disproving the account he had just given.

[Since the date of this meeting, I have found that a full account, agreeing in all essential respects with my own observalion~, wag given by Dr. Karel Sulc in &it. fiir Wissen. Zool. Bd. 99, pp. 147 et sep. (Nov. 1911).-C. J. G.]

HanrILTori DRUCE exhibhd about 30 specimens of H e m w is tityus (bornbylijormis) and H . fuciforniis, which he had taken near Brockenhurst on itby 18th, 19th, 20th, and remarked that the extensive wood cutting in the Forest had not depleted their numbers.

Papers.

BOTH SPECIES OF HEMARIS FROM THE NEW FOREsT.--&h.

The following Papers were read :- ‘I Studies in Rhyncophora, iv; a preliminary note on the

Male Genitalia,” by DAl71~ SHARP, l f .A. , M.B., F.R.S., etc. ‘. Notes on the Ontogeny and Morphology of the Male

Genital Tube in Coleoptera,” by FREDERICK MUIR, F.E.S. “ Notes on various Species of the American Genus Astylus,

Cast. (Coleoptera), with Descriptions of their Sexual Charac- ters,” by G. C. CHAMPION, A.L.S., F.Z.S.

.‘ New Staphylinidae from Singapore, pt. ii,” by NALCOLM CANERON, M.B., R.N.

Wednesday, October Ind, 1918,

Dr. C. J. GAHAN, KA. , D.Sc., President, in the Chair.

Alteration of Bye-law. The proposed alteration in Bye-law viii mas read for the

second time. Exh ibitiorbs.

LIFE-HISTORY OF LYCAENA .ucoN.-Dr. CHAPMAN exhibited a bred specimen of Lycuelaa alcorb, probably the first specimea

.

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that has been bred, certainly the first from larvae taken in the autumn, and made the following observations :-

The life-history is interesting as parallel to, but differing from, that of fijcacna arioji. The young larva feeds in the autumn in the flowers and other portions of Gentiana pneum- lzatbthe, and probably of other Gentians. So far i t is exactly parallel in growth to other Blues, such as many of our Plebeiids that pass the minter in the third instar; when it reaches the third instar it leaves the plant, wanders off, and, hitherto, efforts to carry i t further have failed. At this point it a,gees with L. arioiz in habits, but i t is not like L. nrioa, which.& in a remarkably mo-dified and concentrated (tts regards skin armature) fourth instar, but is in quite an ordinary third instar. In its plant life i t has differed also in that several, often five or six, larvae live amicably in one flower, whereas L. arim is solitary, and if by any accident two larvae meet, as by a second egg having been laid on the same flower-head, or especially when incautiously associatcd in captivity, they are inveterate cannibals.

The remaining history is that both arion and alcon live in the nests of ants-I kept both species in those of Ml,rmica scabrindis-and pupate in the nest (re L. arion, teste Capt. E . B. Purefoy). The differences are that L. arion eats the ant brood, whereas L. alma certainly sucks their juices without eating them, and I could not prove that i t ever actually ate them, though I thought i t did so when past the winter, when its food would more often he an t pupae. L. arion is in its fourth instar, and provided with a skia

armature not unsuitable to i t when full grown. L. alcon has only a third-instar armature, and when full grown might alniost be described as without one, for, like L. arion, i t does not moult after entering the ants’ nest, but attains its full growth still in the third instar. The skin is then so attenuated that the fat-masses are very obvious: and its general aspect is like that of an internal feeder rather than that of a butterfly. It is to be noted as exceedingly remarkable that a butterfly larva should attain its full growth after only two nioults.

Monsieur Oberthiir, who is familiar with localities where L. alcon is common, and considered it highly probable that it

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had a history similar t o that of L. arion, and who with the assistance of Mr. H. Powell found that ants would carry off the larva of L. ulcoii, and that i t wo111d lap up the juices of wounded ant larvae, provided me with the young larvae for observation, in both 1916 and 1917, and my success in rearing the insect is entirely due to his initiative.

My detailed notes have been sent to him to appear in the ‘I Etudes de L6pidoptCrologie compar6e.”

DIr. Powell has seen the larva of L. alcoii carried off by Tetranaorium caespitum and by Tapirtoma erraticum. Acting on this hint Mr. Donisthorpe provided himself with a nest of Tetramoriurn, and now has a larva of L. alms thriving in it. I have larvae in nests of Mpmica scabrind& and M. laevit~dis.

THORPE exhibited a specimen of the common Cockroach (Blatta orientalis) taken under bark of oak in the New Forest, far away from any houses, July 29th, 1918. Dr. NEAVE and the PRESIDENT commented on this exhibit.

THORPE also exhibited a curious ergatandromorph of M. 5trlOdnodi.s taken on Rloxworth Heath, from the collection of the late Rev. 0. Pickard, Cambridge, LARVAL SKINS OF DYTISCUS MARGINAL IS.-^. HUGH MAIB

exhibited the three larval skins of Dytiscus marghalis, pre- pared for demonstration purposes. Ova were deposited in captivity about the last week in May of this year. The larvae hatched on June 4 and 5. The fir& moult of one of the larvae took place on June 13, the second nioult on June 28, and the pupa was disclosed on July 28. The other Iarvae passed through the sanie stages round about the same dates. The empty larval skins were floated out and spread on glass under water, and after drying were mounted up with a cover glass like B lantern slide, strips of cardboard being inserted to prevent pressure on the specimens.

EXPERIMZNTS IN COLOUR-INHERITANCE IN PEDICULUS EUMANUS.-&. BACOT, in referring to some breeding experi- ments he had conducted respecting the inheritance of dark and light coloration in Pediculus huttiantis, explained that his results, which were of an indefinite character, were corn-

AN OUTDOOR SPECIMEN OF THE COCICROACH.-‘Mr. DONIS-

ERGATANDROYORPII OF MYRMICA SULCINOD1S.-&. DONIS-

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pletely valueless owing to the discovery by Sikora that thew insects reacted phototropically to the light or dark hue of their surroundings. It appeared that the factors necessary to the production of dark pignientation were exposure in some earlier instar to light while in a dark environment. Individuals kept in complete darkness did not react. In his exprinients a strain of lice which showed only pale greyish forms during the first three or four generations then com- menced to produce dark (so-called melanic) individuals, presumably owing to the white sides and grey flannel in the box having been blackened with excrement by the insects during this period. With regard to the lengthy series of breeding experiments he had carried out the results curiously simulated some features of discontinuous variation, suggesting Nendelian inheritance in which the proportion of dark and light forms did not conform to theory. It appeared, in view of Sikora’s discovery, that this mas to be accounted for by the chance exposure to light of susceptible larvae or nymphs while amid dark surroundings during examination ; the snutll glase-bottomed boxes in which the broods were reared being normally carried wrapped up in paper in a ve3t pocket, where little, if any, light could penetrate. The nature of the darkening was apparently twofold : (1) dependent upon the pignientation of the chitinised plates, and (2) to t>he suffusion of the general skin surface. His own results suggested that, while the first character niight be present without the second, the second was always accompanied by the first.

P a p - . The following paper was read, the author illustrating his

subject with photographs shown in the epidiascope. ‘i Notes on Australian Sawflies, especially Aut.hors’ Types ’

and the Specimens in the British Museum of Natural Historp and the Hop Collection in the Oxford University Mweum, with Diagnostic Synopses of the Genera and Species,” by the Rev. F. D. 3lORK’E, L4., F.E.S.