Pe TOPE REPORTS VOL. N. | £90 3—T G06 EDITED BY SOWARD B. POULTON;: D.Sc, Mx ; Hon. LL.D. Princeton, F.R.S., F.L.S., F.Z.S., F.G.S., F.ES. HOPE PROFESSOR OF ZOOLOGY IN THE UNIVERSITY OF OXFORD FELLOW OF JESUS COLLEGE, OXFORD MEMBRE HONORAIRE DE LA SOCIETE ENTOMOLOGIQUE DE BELGIQUE CORRESPONDING MEMBER OF THE ACADEMY OF SCIENCE, NEW YORK, AND THE SOCIETY OF NATURAL HISTORY, BOSTON OXFORD PRINTED FOR PRIVATE CIRCULATION BY HORACE HART, PRINTER TO THE UNIVERSITY 1906 ro ay ry * > - 7 af ASL tT ay Se 4 De Racine si = EN. - ee Xe) fo Wit -LIAM © IN NDER, 186°) —\ THE MAKERS OF THE HOPE DEPARTMENT OXFORD UNIVERSITY MUSEUM ENT fae MOreE REPORTS pes) roeg—- 1500 EDITED BY EPDWAKL) G. POULTON, D:Sc;,, M.A, Hon, LD; PRINCETON, EVR.S:, EL-S., B.Z.8., E.G.s., 1.E:S. HOPE PROFESSOR OF ZOOLOGY IN THE UNIVERSITY OF OXFORD FELLOW OF JESUS COLLEGE, OXFORD MEMBRE HONORAIRE DE LA SOCIETE ENTOMOLOGIQUE DE BELGIQUE CORRESPONDING MEMBER OF THE ACADEMY OF SCIENCE, NEW YORK, AND THE SOCIETY OF NATURAL HISTORY, BOSTON OXFORD PRINTED FOR PRIVATE CIRCULATION BY HORACE HART, PRINTER TO THE UNIVERSITY 1906 "a PREEAC E Tue fifth volume of Hope Reports contains a variety of memoirs chiefly published in 1904 and 1905, but some few of them overlapping into 1903 and 1906. Almost the whole of the included publications deal with bionomic subjects, or subjects whose chief interest is bionomic. The two Presidential Addresses of the Hope Professor to the Entomological Society (3 and 4) attempt to deal with very broad and fundamental questions, which, however, are regarded principally from the bionomic standpoint. Mr. Edward Saunders’ important faunistic memoir (13) on the Aculeata of Majorca and Spain contains an appendix and notes on bionomic subjects by the Professor. Excluding the two Presidential Addresses, from the ‘ Proceedings of the Entomological Society of London’ (3 and 4), and paper (2) contributed to the French Entomological Society, memoirs 5-14 inclusive are published in the ‘ Transactions’ of the London Society; and I desire to express my warm appreciation of the ready and sympathetic help always received from the Officers, Council, and Fellows, who have permitted me thus to issue privately these sefarata from their publications. ae ane d The ten memoirs (5-14) from the ‘Transactions of the Entomological Society’ are the work of eight authors, of whom six—viz. all except Mr. Edward Saunders, F.R.S., and the Professor—now appear for the first time in a 4 PREFACE volume of Hope Reports. Mr. H. A. Byatt’s estimate of the numerical proportion between a mimetic butterfly hitherto regarded as excessively rare and its abundant model (12) is based on an examination of material I never expected to be fortunate enough to see. Exact observa- tions on the attacks of parasitic insects are always difficult to obtain, and Mr. F. P. Dodd’s paper (14) is corre- spondingly valuable, all the more so because of the de- scription of new species in the Appendix by Col. C. T. Bingham and Dr. Wandolleck. After a long interval of time, Mr. Roland Trimen’s association in 1869 of the wonderful series of mimetic females of Papzlio dardanus (merope) with each other and with an entirely different non- mimetic male, receives its absolute confirmation (in 1902-3) by the careful breeding experiments of Mr. G. F. Leigh (11). Three papers contain the observations of Dr. G. B. Longstaff. The first of these (8), a memoir of over eighty pages, records his notes on butterflies made in a tour through India and Ceylon in 1903 and 1904. It abounds in descriptions of the habits and special localities of these insects, their flight, attitudes, gregarious habits, scents, &c. The symmetrical injuries probably caused by enemies, observations of ‘list,’ of scents, and of seasonal forms are conveniently summarized at the end of the paper. Dr. Longstaff’s second paper (9) gives an account of his obser- vations in 1905 upon the cryptic and mimetic resemblance, as well as the actively defensive methods, of certain South African Cetonzinae and Hlopliinae. His third paper (10) contains a further account of the rest-attitudes of butterflies, —‘heliotropism,’ ‘inverted attitude of Lycaenids,’ ‘ tilt to one side or “list”,’ and general remarks. Major Neville Manders contributes material which throws light on two most difficult questions,—the seasonal changes ~ PREFACE 5 of the Prervznae and the migrations of butterflies (7). The valuable paper on the ants, wasps, and bees of Majorca and Spain (13), by Mr. Edward Saunders, F.R.S., has been already referred to. Mr. Abbott H. Thayer, who origi- nated the classical interpretation of the white under-sides of animals, contributes a most interesting memoir (5) on Protective Coloration. His conclusions, mainly accepted, are in certain respects criticized by the Professor (6). A communication by the Professor to the Entomological Society of France attempts to explain the meaning of the eye-like spots on the wings of Satyrine and Nymphaline butterflies (1). A special characteristic of the present volume is the large collection of short communications, almost exclusively upon bionomic subjects, from the ‘ Proceedings of the Entomo- logical Society of London,’ from October 7, 1903, to March 21, 1906. The whole forms a list of exhibitions, notes, discussions, and short papers contained in Nos. 15-21 inclusive of the present volume. It is hoped that all will be easily traced under sufficiently descriptive titles, eighty- nine in number, arranged in order of date, in the Table of Contents. Dr. Dixey’s name appears as the author of considerably over a dozen communications, including accounts of his and Dr. Longstaff’s highly important observations on the scents of butterflies, and of his own researches into sea- sonal forms and cryptic and mimetic coloration in certain Pierinae. Dr. Longstaff presented five communications, principally dealing with the attitudes of insects and their bionomic significance, but also including valuable obser- vations on the scents of male butterflies of the Pierine genus Gonepteryx. Interesting observations made by Mr. A. H. Hamm were the subject of communications and 6 PREFACE exhibitions on five occasions. Five communications also appear under the authorship of Commander J. J. Walker. A specially interesting feature in the long list printed in the Contents is the constant recurrence of the names of naturalists in other lands as the authors of commu- nications. Thus the observations of Mr. S. A. Neave were made in North-Eastern Rhodesia, Mr. C. N. Barker and Mr. G. F. Leigh in Natal, Dr. S. Schonland in British Bechuanaland, Mr. C. A. Wiggins in British East Africa and Uganda, while Mr. H. A. Byatt dealt with material from the sources of the Congo. It is also a great pleasure to welcome communications from naturalists of the United States,—Professor W. J. Holland of Pittsburg, Professor Vernon L. Kellog of California, and Mr. Abbott H. Thayer of New Hampshire. Mr. J. C. Kershaw’s observations were made in the neighbourhood of Macao and Hong Kong, Mr. F. P. Dodd’s in North Queensland, Major Neville Manders’ in Ceylon, Mr. L. Andrewes’ in Southern India. Finally, a full account of the progress of the Hope Department during the years 1903, 1904, and 1905 will be found in the Reports of the Professor (22-24). Nearly three years have elapsed since the appearance of the fourth volume of Hope Reports, dated Nov. 9, 1903; but the volume now issued by no means represents the whole of the research in the Department or upon its material. Certain memoirs, published in large octavo or quarto, cannot be accommodated to the size of the present volumes. These larger papers are gradually accumulating until their numbers will admit of a special issue. Several memoirs now going through the press were written within the period covered by volume V. The manuscript for a complete volume on the W. J. Burchell Collections was PREFACE 7 all but finished a year ago: but publication has been delayed for a time in the hope that further manuscript bearing on the collections may be discovered (see 21, 6. 1). When the volume devoted to the memory of Burchell makes its appearance, it will not, like its predecessors, be ‘printed for private circulation,’ but will be freely accessible to the public. EDWARD. .b.. POULTON. HOPE DEPARTMENT OF ZOOLOGY, UNIVERSITY MUSEUM, OXFORD, June 25, 1906. rs st CONTENTS, OF VOL. V . Preface. . Signification bionomique des taches ocellaires chez les Satyrinae et Nymphalinae, by Edward B. Poulton, D.Sc., M.A., Hon. LL.D. Princeton, F.R.S., &c., Hope Professor of Zoology in the University of Oxford, Fellow of Jesus College, Oxford. (From ‘Annales de la Société Entomologique de France,’ vol. Ixxii, 1903, p. 407). . ‘What is a Species?’ The Presidential Address read before the Entomological Society of London at the Annual Meeting, Jan. 20, 1904, by Professor Edward B. Poulton, (From ‘ Proceedings of the Entomological Society of London,’ 1903, p. xxvii.) . The Bearing of the Study of Insects upon the Question ‘Are Acquired Characters Hereditary?’ The Presidential Address read before the Entomological Society of London, at the Annual Meeting, Jan. 18, 1905, by Professor Edward B. Poulton. (From ‘ Proceedings of the Entomological Society of London,’ 1904, p. civ.) . Protective Coloration in its Relation to Mimicry, Common Warning Colours, and Sexual Selection, by Abbott H. Thayer. (From ‘Transactions of the ‘Entomological Society of London,’ 1903, P. 553-) . A brief Discussion of A. H. Thayer’s Suggestions as to the Meaning of Colour and Pattern in Insect Bionomics, by Professor Edward B. Poulton. (From ‘Transactions of the Entomological Society of London,’ 1903, p. 570.) . Some Breeding Experiments on Cavopsilia pyranthe and Notes on the Migration of Butterflies in Ceylon, by Major Neville Manders, R.A.M.C., F.Z.S., F.E.S. (From ‘ Transactions of the Entomological Society of London,’ 1904, p. 701.) . Notes on the Butterflies observed in a Tour through India and Ceylon, 1903-4, by G. B. Longstaff, M.D., M.A., Oxon., F.E.S., New College, Oxford. (From ‘Transactions of the Entomological Society of London,’ 1905, p. 61.) Io CONTENTS OF VOL. V g. On some Bionomic Points in certain South African Lamellicorns, by Dr. G. B. Longstaff. (From ‘Transactions of the Entomological Society of London,’ 1906, p. gt.) 10. Some Rest-Attitudes of Butterflies, by Dr. G. B. Longstaff. (From Il. I2. 13. 14; rs. ‘Transactions of the Entomological Society of London,’ 1906, p. 97.) Synepigonic Series of Papilio cenea (1902-3) and Hypolimnas misippus (1904), together with Observations on the Life-History of the former, by George F. Leigh, F.E.S., with Notes by Professor Edward B. Poulton, and an Appendix by Roland Trimen, Hon. M.A. Oxon., F.R.S., F.E.S. (From ‘Transactions of the Entomological Society of London,’ 1904, p. 677.) Pseudacraea pogget and Limnas chrysippus ; the Numerical Proportion of Mimic to Model, by Horace A. Byatt, B.A., F.E.S., Lincoln College, Oxford, with a note by Professor Edward B. Poulton. (From ‘Transactions of the Entomological Society of London,’ 1905, p- 263.) Hymenoptera Aculeata from Majorca (1901) and Spain (1901-2), by Edward Saunders, F.R.S., F.E.S., &c., with an Introduction, Notes, and Appendix (on Mimicry of Aculeata by Asilidae and Volu- cella) by Professor E. B. Poulton. (From ‘Transactions of the Entomological Society of London,’ 1904, p. 591.) Notes upon some Remarkable Parasitic Insects from North Queensland, by F. P. Dodd, F.E.S., with an Appendix containing Descriptions of New Species by Col. C. T. Bingham, F.Z.S., F.E.S., and Dr. Benno Wandolleck, of Dresden. (From ‘Transactions of the Entomological Society of London,’ 1906, p. 119.) Extracts from the ‘ Proceedings of the Entomological Society of London,’ October-December, 1903, containing the following communica- tions :— a. Oct. 7, 1903.—1. The group of Butterflies mimicking Planema pogget, together with the description of a new mimetic female form of Papilio dardanus (merope), the planemotdes form, by Roland Trimen, F.R.S. 2. Discussion of the above, with a list of the further members of the same mimetic group discovered by S.A. Neave, B.Sc., B.A.,F.E.S., Magdalen College, Oxford, by Professor Edward B. Poulton. b. Oct. 21, 1903.—1. Forms of J/elitaea aurinia captured by A. H. Hamm. CONTENTS OF VOL: V TI 2. Suggested interpretation of the hooked apex of the fore-wing and produced angle of the hind-wing in dry-season butterflies, by Professor Edward B. Poulton. 3. Note on the above communications, by W. J. Kaye, F-.E.S. c. Nov. 4, 1903.-—Exhibition of 323 butterflies captured Aug. 28, 1903, in British Guiana: list of species and discussion of the mimetic groups, by Professor Edward B. Poulton. d. Nov. 18, 1903.—1. Absence of the eyes of Ennomos autumnaria when the corresponding structures of their larvae had been covered by an opaque varnish, by Professor Edward B. Poulton. 2. A diagram which suggests that submarginal white spots on dark butterflies are of value in rendering the margins less recog- nizable, by A. H. Thayer, of Monadnock, N.H., U.S.A. 3. Papilio (Drurya) antimachus, a member of the great mimetic group clustered round Acraea egina: the pressure of the struggle for existence on insect-eating animals immensely increases the severity of their attacks upon insects, and in such a manner as to promote Miillerian mimetic likeness, by Professor Edward B. Poulton. 4. Mimetic resemblance independent of size because size is a cor- relative of distance, by F. A. Heron, M.A., F.E.S., New College, Oxford. e. Dec. 2, 1903.—1. Photographs showing the flower-like colours and patterns of butterflies’ wings, by A. H. Thayer. 2. The Eyeless Examples of £. autumnaria described on Nov. 18, 1903, by Professor Edward B. Poulton. 16. Extracts from the ‘ Proceedings of the Entomological Society of London,’ Feb.—March, 1904, containing the following communications :— a. Feb. 3, 1904.—Exhibition of the material described in memoir No. 11, by G. F. Leigh. 6. March 2, r904.—1. The mimetic resemblance of the Indian Longi- corn beetle Glenea pulchella to an Ichneumonid, by Leslie Andrewes. 2. Discussion of G/enea and other mimetic Longicorns, by Prcfessor Edward B. Poulton. 3. The ‘Bugong’ used as food by Australian natives is a moth and not a Danaine butterfly: the explanation of erroneous state- ments on the subject, by F. A. Dixey, D.M., M.A., Oxon., F.E.S., Fellow and Bursar of Wadham College, Oxford. 12 CONTENTS OF VOL. V 4. The identity of the ‘Bugong,’ by Commander J. J. Walker, Hon. M.A. Oxon, F.L.S., F.E.S., and C. O. Waterhouse, F.E.S. 5. Discussion on the subject of the Presidential Address, ‘What is a Species?’ (Memoir No. 3), by Rev. F. D. Morice, M.A., Fellow of Queen’s College, Oxford; Dr. F. A. Dixey; A. J. Chitty, M.A., F.E.S., Balliol College, Oxford; H. J. Elwes, |.2., &.R:S., F.LS,,. F.Z.5.,. FES. 2 Wn Ba ode, peek ea. T. A. Chapman, M.D., F.Z.S., F.E.S.; and Professor Edward B. Poulton. c. March 16, 1904.—1. Exhibition of the ‘ Bugong’ moth, Agrofis spina, and of an apparently mimetic Australian Geometrid moth, by Commander J. J. Walker. 2. A remarkable pale form of A/amestra brassicae from North Devon, by Dr. F. A. Dixey. 3. The Gregarious Hybernation of certain Californian Insects, by Professor Vernon L. Kellog, Leland Stanford Junior University, California. 4. A possible explanation of insect swarms on mountain-tops, by Professor Edward B. Poulton. 5. Discussion of the above, by Dr. T. A. Chapman; Commander J. J. Walker; A. J. Chitty; G..C. Champion, F.Z.S., F-ES.; Col. J. W. Yerbury, F.L.S., F.E.S. ; Col. C. Swinhoe, Hon. M.A. Oxon., F.L:S., F.Z.S., F.E.S. 3, Dr. F. A. Dixey ;-H. Rowland- Brown, M.A., F.E.S., University College, Oxford ; J. W. Tutt, BESS. ; Col-C. FT. Bingham, F2Z:S.,-F-E.S; rev. 2. 1D. Monce; H. St. J. K. Donisthorpe, F.Z.S., F.E.S.; and Professor E. B. Poulton. 17. Extracts from the ‘Proceedings of the Entomological Society of London,’ May-June, 1904, containing the following communica- tions :— a. May 4, 1904.—1. Exhibition, by G. H. Verrall, F.E.S., of the Asilid fly Veottamus cothurnatus, captured for the first time in England by W. Holland. 2. The Resemblance between the S. African Longicorn beetle Nitocris nigricornis and a Bracon, by C. N. Barker, F.E.S. 3. Record of an attack. by a bird on the Indian butterfly Zvymnias undularis, by Professor E, A. Minchin, M.A. Oxon., Keble College, Oxford. 4. A Chinese Cuckoo attacking Hesperid larvae, by J. C. Kershaw, FES. CONTENTS OF VOL. V 13 6. June 1, 1904.—1. The offensive smell of the African ant Paltothyreus tarsaius, by Dr. S. Schonland, Ph.D., Hon. M.A. Oxon., Curator of the Albany Museum, GraHamstown. 2. The oviposition of Vanessa urticae, by A. H. Hamm. 3. The courtship and pairing of Vanessa: urticae, by Professor Edward B. Poulton. 4. Further notes on the above communication, by A. J. Chitty. 5. Description of forms of Zredia evias and E. stygne captured by E. B. Poulton at La Granja, Spain, by Dr. T. A. Chapman. 6. Communication of ‘Synepigonic Series of Papzlio cenea (1902-3) and of Hypolimnas misippus (1904), &c., by G, F, Leigh (Memoir No. rr). 7. Communication of ‘ Hymenoptera Aculeata from Majorca (1901) and Spain (1901-2), by Edward Saunders, F.R.S., F.L.S., F.E.S. (Memoir No. 13). 18. Extracts from the ‘Proceedings of the Entomological Society of London,’ June-Dec., 1904, containing the following communica- tions. [There is here a slight overlap, and Nos, 6 and 7 in the above list are repeated. |— a. June 1, 1904 (continued).—1. Abstract of ‘Some Breeding Experiments on Catopsila pyranthe, and Notes on the Migration of Butter- flies in Ceylon,’ by Major Neville Manders (Memoir No. 7). 2. Discussion of the above memoir, by Dr, F. A. Dixey. b. Oct. 5, 1904.—1. Exhibition of preparations of the scent of male Pierine Butterflies, together with an account of methods and observations, by Dr. F. A. Dixey. 2. Discussion of the above, by Professor R. Meldola, F.R.S., F.E.S., Rev. F. D. Morice, Colonel C. T. Bingham, &c. Oct. 19, 1904.—Exhibition of Bees of the genus Sphecodes, captured with a mimetic Fly in a single sweep of the net, by Professor E. B. Poulton. d. Nov. 2, 1904.—1. Pierts rapae seeking a white dahlia for a nesting site, by A. H. Hamm. 2. Colras edusa resting on yellow flowers, by Dr. T. A. Chapman. 3 3- Specimens of the Reduviid bug, Conorrhinus (Lamus) megtstus, captured by W. J. Burchell in Brazil, together with his notes showing that the species attacks man, by Professor E. B. Poulton. e. Nov. 16, 1904.—1. The British Diptera collected by W. J. Burchell, by Professor E. B. Poulton. 14 CONTENTS OF VOL. 2. African caterpillar skins preserved by W. J. Burchell, together with an account of his methods, by Professor E. B. Poulton. J. Dec. 7, 1904.—1. Passalid beetles captured in Brazil by W. J. Burchell, together with his record of their sound, by G. J. Arrow, F.E.S. . Two beetle larvae, captured by W. J. Burchell in Brazil, together with his observations on them, by C. O. Waterhouse. 3. The type of Haplothorax burchelli captured by Burchell in St. Helena, by Commander J. J. Walker. 4. Specimens of Papilio dardanus (cenea) bred from a ¢rophonius form of female, by G. F. Leigh. 5. Aseries of individuals connecting Crastia amymone and C. godartt, from Macao, by J. C. Kershaw. ty 6. Photograph of an Asilid fly and its Xylocopid model, from Ceylon, exhibited by Professor E. B. Poulton. 7. Abstract of ‘Notes on Butterflies observed in a tour through India and Ceylon, 1903-4,’ by Dr. G. B. Longstaff (Memoir No. 8). 19. Extracts from the ‘Proceedings of the Entomological Society of London,’ March—June 1905, containing the following communica- tions :— a. March 1, 1905.—1. Cocoons and perfect insects of Hybrid Saturnias, together with notes on breeding these specimens and S. pavonza, by Dr. F. A. Dixey, 2. Mimetic groups of Hymenoptera and Diptera, by A. H. Hamm. 3. Excessively worn specimens of Papilio hesperus from Entebbe, still retaining the ‘ tails’ of the hind-wing, by C. A. Wiggins, M.R.C.S. 4. Nymphaline mimics from W. China (‘ Northern’ is printed by mistake in the ‘ Proceedings’) of ypolimnas mtsippus, unknown in that country, by Professor E. B. Poulton. b. March 15, 1905.—South African Butterflies of the genera Crenzs, Pinacopteryx, and Teracolus, bred under various conditions by Guy A. K. Marshall, F.Z.S., F-E.S., by Dr. F) A. Dixey. c. April 5, 1905.—1. The web and pupal cases of the Mexican Pierine butterfly Lucheira socialis, by Dr. F. A. Dixey. 2. Further notes on the above communication, by Dr. W. J. Holland, of Pittsburg, Pa., U.S.A. 3. Superstitious dread in N.E. Rhodesia of a Sphinx larva with eye-like marks, by S. A. Neave, B.Sc., B.A., F.E.S., Magdalen College, Oxford. CONDENS OF VOLES V 15 4. Communication of.‘ Pseudacraea pogget and Limnas chrysippus ; the Numerical Proportion of Mimic to Model,’ by H. A. Byatt (Memoir No. 12). d. May 3, 1905.—1. Interesting insects captured near Oxford, by Commander J. J. Walker. 2. The type specimen of Denoderus ocellaris, Steph., by Commander J. J. Walker. 3. Heliotropism in the butterflies of the genera Pararge and Pyra- mets, by Dr. G. B. Longstaff. 4. Discussion of the above paper, by Dr. W. J. Holland, F. E. Merrifield, F.E.S., C. O. Waterhouse, G. C. Champion, &c. e. June 7, 1905.—1. Leaves of plants attacked by fungi the probable models of AKa/ma with its transparent ‘windows,’ by W. B. Grove. 2. The details of resemblance to fungus upon the wings of Ka/lima, by Professor E. B. Poulton. 3. Scents of the male butterflies of the genus Gonepteryx, by Dr. G. B. Longstaff. 4. Exhibition and discussion of butterflies of the genus Gonepreryx, by Dr. F. A. Dixey. 2c. Extracts from the ‘ Proceedings of the Entomological Society of London,’ Oct.—Dec., 1905, containing the following communications :— a. Oct. 18, 1905.—Exhibit of interesting insects from Sarawak, Borneo, by R. Shelford, M.A. (Cantab.), F.L.S., F.Z.S., F.E.S. é. Nov. 1, 1905.—The scents of S. African Pierine Butterflies, by Dryk. A. Dixey: c. Nov. 15, 1905.—1. Wet- and dry-season forms of S. African Pierine Butterflies, by Dr. F. A. Dixey. 2. Discussion on the above communication by Col. J. W. Yerbury and Professor E. B. Poulton. d, Dec. 6, 1905.—1. Geographical and seasonal variation in five species of S. African Pierine Butterflies, by Dr. F. A. Dixey. 2. Notes on the larvae of the beetles Collyrzs marginatus and Mor- molyce, by R. Shelford. 3. The choice of appropriately coloured resting sites by Prerzs rapae, by A. H. Hamm. 4. Discussion of the above communication, by H. J. Elwes, Col. J. W. Yerbury, H. Rowland-Brown, G. C. Champion, &c. 5- Discussion of the above, with suggestions as to the origin of the instinctive preference, by Dr. T. A. Chapman. 16 CONTENTS OF VOLAW 21. Extracts from the ‘Proceedings of the Entomological Society of London,’ Feb.—March, 1906, containing the following communica- tions :— a. Feb. 7, 1906.—1. Scents of S. African Danaine, Satyrine, Nymph- aline, Acraeine, and Papilionine Butterflies, by Dr, F. A. Dixey. 2. Discussion of the above communication, by Rev. A. E. Eaton, M.A., F.E.S.,G. C. Champion, Dr. G. B. Longstaff, J. W. Tutt, Professor E. B. Poulton, Dr. F. A. Dixey, &c. 3. Four interesting species of Acraea from the neighbourhood of the Victoria Falls, by Dr. G. B. Longstaff. 4. The fly Chortophila unilineata, following the bee Andrena labialis, by A. H. Hamm. 5. Discussion of the above communication, by Rev. A. E. Eaton and Professor E. B. Poulton. b. March 7, 1906.—1. W. J. Burchell’s Original African Journal from May 24 to Sept. 2, 1812, by Professor E. B. Poulton. 2. The eye-like spots on the elytra of the chafer Lepidvota bimaculata, by Professor E. B. Poulton. 3. The reddish tints of the under-sides of dry phase Pierine Butter- flies in many parts of the world, by Dr. F. A. Dixey. 4. Abstract of ‘Notes upon some Remarkable Parasitic Insects from North Queensland,’ by F. P. Dodd, F.E.S. (Memoir No. 14). 5. Communication of ‘Some Rest-Attitudes in Butterflies, by Dr. G. B. Longstaff (Memoir No. 10). 6. Discussion of the above communication, by Dr. T. A. Chapman, Professor E. B. Poulton, Dr. F. A. Dixey, &c. c. March 21, 1906.—Mimicry of other butterflies, chiefly Pierines, by the related Pierine Genera Lronia, Nepheronia, and Leuceronia, by Dr. F. A. Dixey. 22. Report of the Hope Professor of Zoology for 1903. (From the ‘Oxford University Gazette.’) 23. Report of the Hope Professor of Zoology for 1904. (From the ‘Oxford University Gazette.’) 24. Report of the Hope Professor of Zoology for 1905. (From the ‘Oxford University Gazette.’) a Extrait des Annales de la Société Entomologique de France, 1903. LA SIGNIFICATION BIONOMIQUE DES TACHES OCELLAIRES DES PHASES DE LA SAISON HUMIDE CHEZ LES SATYRINAE ET NYMPHALINAE par le Prof. Edward B. Poutron (*). |Planche VI]. —<»“S>— Depuis longtemps on a reconnu que les formes de la saison humide chez les Satyrinae sont caractérisées par la quantité et Papparence distincte des taches ocellaires sur la face inférieure des ailes. Dans la durée de la saison seche, chez ces mémes espeéces, les taches ocellaires sont tres petites ou tres souvent absentes. La signification de cette dil- férence et la cause de son origine furent un grand mystere ; mais récem- ment la lumiére se fit sur cette question lorsqu’on eut reconnu qu'une différence de méme nature existe entre les phases saisonniéres de cer- taines espéces du groupe des Nymphalidae (Precis ou Damonia). Dans la forme de la saisonseche du Precis artariadu Sud Africain, on remarque que la face inférieure des ailes ressemble a une feuille morte @une ma- niére remarquable. D’autre part, la forme de la saison humide présente une marge blanche visible et des taches ocellaires sur la face infé- rieure. De méme chez Pespece commune orientale, Precis almana, les nombreuses et tres visibles taches ocellaires de la phase humide (as- teria) sont réduites a de minuscules points ressemblant aux petites taches noires de moisissures poussant sur la similifeuille morte de la phase seche. Cette ressemblance entre les Sutyrinae et les Nympha- linae est tres importante. Quand les deux formes des espéces de Sous- Familles aussi différentes que les Satyrinae et les Nymphalinae réa- gissent de la méme maniere particuliere aux deux saisons, nous pouvons affirmer d’une maniere presque certaine que nous sommes en face d’un phénomene d’adaptation. Nous voyons un état de choses dont la raison d’étre provient @un avantage gagné dans la lutte pour la vie. (1) Ce mémoire est un résumé des principaux points exposes par notre col- legue, M. E. Poulton, professeur de Zoologie a l'Université d’Oxford, dans lintéressante conférence faite par lui 4 la Séance du 22 avril 1903 (Cf. Bul. Soc, ent. Fr. [1903], p. 160), (Note du Secrétaire.) Epwarp B. PouLton. 408 Jai récemment discuté la signification des differences saisonnieres chez les Nymphalides du genre Precis (Trans. Ent. Soc. Lond., 1902. pp. 414-458). Mais plus mire réflexion sur le sujet, et surtout la con- versation que j’ai eue avec le collegue a qui je dois tant, M. le D' F. A. Dixey M. D. de Wadham College, Oxford, ont eu pour résultat addition de nouveaux détails importants aVinterprétation que j'avais donnée lan dernier. Le contact de deux esprits produit des idées nouvelles a tous deux, comme lunion de deux cellules germinales qui donne naissance aun nouvel étre, — étre possédant ses qualités propres, — et non un simple intermédiaire entre les parents. Ici je voudraisaltirer votre attention surle terme Bionomique introduit par mon ami le Professeur E. Ray-Lankester comme !e mot Je plus con- venable pour exprimer les rapports entre les organismes vivants. Cette addition importante a notre terminologie décharge le mot Biologie de toute signification, excepté celle du terme général sous lequel sont rangés tous les sujets de Zoologie et de Botanique. C’est dans Vétude bionomique des Insectes que nous pouvons espérer découvrir linter- prétation du développement spécial des taches ocellaires dans les phases de la saison humide. Certaines observations sembilent jeter la lumiere sur ce pro- bleme : En 1887, j'ai observé un Lézard étudiant avec un grand intérét la tache ocellaire placée 4 la face inférieure de Vaile antérieure du Papil- lon commun Coenonympha pamphilus. Plusieurs fois le Lézard essaya de mordre cette partie de Vaile. En 1899 M. Marshall observa qu'un rapace fit sa premiere attaque sur les taches ocellaires des ailes posteé- rieures @un Papilio demodocus qui lui avait été offert. M. Marshall a aussi capturé un grand nombre de papillons du Sud Africain qui pré- sentent des déchirures sur les taches ocellaires ou dans leur voisinage. (Trans. Ent. Soc. Lond., 1902, p. 366.) Le témoignage de tels faits justifie opinion que les taches ocel- laires sont des marques destinées 4 attirer Vattention de V’ennemi et a protéger ainsi l’Insecte d'une blessure mortelle. Par consequent le papillon atlaqué aura une chance de plus d’échapper au danger. Cette interprélation est encore appuyée par la distribution sur les ailes des taches ocellaires de la saison humide. Elles ne sont pas placées pres du corps, contrastant sensiblement de cette facon avec beaucoup de marques indicatrices d'un gout nauséabond (warning or aposematic marks), telles que la tache rouge a la base de la face in- férieure des ailes chez les Pierides du genre Delias, ou chez les Helico- ninae, ou encore la tache triangulaire @un brun doré marqué de noir 409 Signification bionomique des taches ocellaires chez les Satyrinae. observée dans une position correspondante chez tant de papillons Africains (loc. cit., p. 488). D’autre part, ces taches ocellaires tendent a se développer 4 Vapex de Vaile antérieure et a angle anal de Vaile postérieure. On les trouve ailleurs placées sur les bords les plus ex- ternes des ailes — c’est-a-dire les plus éloignés du corps — ou pres de ces bords. Il y a encore cependant un autre point important dans cette methode de défense. Sa valeur la plus certaine, et probablement la seule, est durant les courts arréts entre les vols successifs @un Insecte, et spé- cialement au moment oti il va se poser. Sans doute Pennemi guette V'Insecte, mesure de lil la place exacte ot il va se poser : c’est le moment choisi pour l’attaque. A cet instant précis les taches ocellaires ont probablement leur plus grande importance et ulilité; mais aussi- tot que Vinstant critique est passé, ces taches tendent 4 devenir dan- gereuses. Elles attirent maintenant Vattention des ennemis qui n’ont pas vu l’Insecte allant se reposer. Par conséquent nous voyons, chez beaucoup de Satyrinae, que cette tache a Vextrémité de Vaile anté- rieure est exposée pendant quelques secondes apres Varrét, puis est cachée par Pabaissement des ailes antérieures entre les postéricures. Il s’ensuit que ces taches sur la face inférieure ont beaucoup plus de valeur pour les Papillons qui volent sans cesse, s’arrétant pour repartir de nouveau pendant de longues heures de soleil, durant leur vie en- tiere. D’autre part ces taches tendent a devenir un danger réel pour les Papillons qui volent moins, et passent beaucoup plus de temps dans Vattitude du repos. Dans ce repos prolongé, excepté pour cer- taines especes nauséabondes, la dissimulation la plus complete est la meilleure défense. Durant cet état de repos les taches ocellaires non seulement constituent un danger en attirant Vattention des ennemis, mais elles sont inutiles pour éloigner celle-ci des parties vitales. Le succes de cette méthode dépend de état du papillon, s’il est ou non prét a la fuite; et lorsqu’un ennemi peut attaquer sans cesse, comme ce serait le cas pour l’Insecte plongé dans un profond repos, une sem- blable défense est naturellement sans valeur. Mais la saison humide est justement le temps oti les Insectes sont le plus nombreux et volent constamment dans chaque rayon de soleil. Tandis que dans la saison séche ils sont beaucoup plus rares et beau- coup moins visibles. En pleine saison seche les Papillons ont Vhabitude de se cacher, traversant peut-étre une sorte de période de repos esti- val afin d@échapper aux effets de la grande sécheresse. Mais quelle qu’en soit la cause, un tel repos prolongé est beaucoup plus str quand la surface des ailes exposée ressemble au milieu environnant, ou bien Epwarp B. PouLTon. AAQ a quelque objet particulier dans ce milieu, tel qu'une feuille morte, qui mintéresse pas les animaux en quéte d’Insectes. Je crois que c’est la le principe dominant qui explique le dévelop- pement des taches ocellaires dans les phases humides, et leur diminu- tion ou leur disparition dans les phases séches chez la méme espéce. Les habitudes dans la saison humide sont telles que ces taches confe- rent aux Papillons un avantage dans la lutte qu’ils ont 4 soutenir contre les ennemis de cette saison; les habitudes dans Ja saison seche sont telles que ces mémes taches favoriseraient les ennemis de cette époque. Cette derniére phrase indiquerait d@autres raisons importantes pour les différentes phases saisonnieres des Papillons. En premier lieu les ennemis qui recherchent et altaquent les Insectes en état @activité se trouvent probablement eux-mémes dans des con- ditions différentes pendant les deux saisons. Ces ennemis sont ou agiles 4 poursuivre un Papillon, ou agiles a fondre sur lui durant un arrét momentané; ou bien ils se posent et attendent sur les plantes que les Insectes recherchent. Ainsi que je Vai déja suggéré, les taches ocellaires sont probablement développées comme moyen de défense contre ces agiles ennemis de la saison humide — Oiseaux ou Lézards actifs. De tels ennemis, surtout les Oiseaux avec leur puissance de vol, ont un grand choix d’Insectes a leur disposition dans la saison humide; par conséquent ils se décideront facilement a abardonner Vattaque sur un Papillon aprés un premier échec. Pendant la saison seche la variété d’Insectes est beaucoup plus restreinte, et les Papil- lons constituent probablement une beaucoup plus grande proportion de la nourriture des insectivores. Les ennemis agiles sont vraisem- blablement dans de telles conditions quils poursuivraient sans remords et renouvelleraient sans cesse leur attaque. Une saveur rela- livement désagréable serait aussi moins puissante a prévenir leur attaque. C’est probablement une des raisons pour lesquelles les faces inférieures des ailes chez certaines autres especes du genre Precis (P. sesamus, P. antilope, P. actia) sont, non ocellées, mais remar- quablement visibles pendant Ja saison humide, tandis qu’elles sont bien dissimulées dans la saison séeche. En second lieu, les ennemis qui attaquent les Papillons durant leur repos prolongé comprennent beaucoup @especes dont les habitudes et les manieres de rechercher leur proie, different entitrement de celles des especes qui poursuivent les Insectes actifs. Ces insectivores re- cherchent soigneusement, systématiquement, chassent partout ott ils peuvent espérer trouver quelque nourriture. Ils sont sans doute moins exigeants dans leurs préférences que les ennemis agiles a la poursuite, M1 = Signification bionomique des taches ocellaires chez les Satyrinae. et ne sont probablement pas repoussés par un gout modérément nau- séabond. Parconséquent, a cause du ralentissement de leur activité etdu temps plus long qu’ils passent en un profond repos, les papillons de la saison seche sont plus exposes aux attaques de ces ennemis. Ces der- niers seraient aidés dans leur recherche par la présence de taches ocellaires ou par toute autre marque visible, et, contre eux, une saveur modérément nauséabonde ne constituerait qu'une défense insul- fisante, Les considérations exposées dans ce mémoire indiquent la raison pour laquelle la sélection naturelle a saisi et développé une sensibilité speciale pour une condition quelconque associée a Pune ou a deux de ces saisons. La nature exacte de la condition a été insuffisamment étudiée, mais c’est probablement le degré variable @humidité qui agit comme stimulant sur les espéces rendues particuli¢rement susceptibles par la sélection naturelle. La susceptibilité est probablement limitée a quelque époque spéciale de leur vie. Par consequent, comme le colonel J.-W. Yerbury I’a observé a Aden (Proc. Ent. Soc. Lond., 1902, mars 19) la chute soudaine @une pluie abondante au milieu d’une saison seche normale est suivie par lapparition a la fois de formes humides, inter- meédiaires, el seches de Pierinae. Ce fait s’explique facilement, comme la suggéré M. le Dé F.-A. Dixey (Trans. Ent. Soc. Lond., 1903, p. 158- 160) par Vhypothése que, a Varrivée de la pluie, quelques-uns des individus étaient a leur époque la plus sensible, d’autres n’étaient que partiellement sensibles, tandis que le reste avait déja cessé détre sen- sible. Si Pon compare la figure 1 sur la planche VI avec la figure 2, on verra que la forme seche du Precis artaxia est beaucoup plus large que la forme humide. Le poids est aussi beaucoup plus grand chez cette espece et chez d’autres especes du genre Precis (Trans. Ent. Soc. Lond., 1902, p. 454 et 454). Tl s’ensuit que dans ces cas, du moins, la période sensible ne peut pas étre plus tardive que lépoque larvaire, alors que le poids de Vinsecte est déterminé. ll est probable que la rapidité plus grande du développement pendant la saison humide, entrainant une diminution dans la taille et dans le poids du Papillon, est aussi un avantage conféré par la sélection naturelle. Le nombre des individus chez plusieurs especes est sans doute relative- ment abaissé dans la lutle excessive pour la vie pendant la saison seche, alors que TPoccasion de compenser les pertes par une rapide succes- sion de générations n’existe pas. Il est par conséquent avantageux pour les especes de s’accroitre aussi rapidement que possible pendant Epwarp B. Poutton. — Les taches ocellaires chez les Satyrinae. 412 le temps oti la nourriture est abondante et la lutte moins apre. Une semblable multiplication est réalisée par le nombre de générations rendu possible par un rapide développement et une diminution dans la taille. Remarquez de plus que, chez le Precis artaxia des foréts profondes, la condition qui agit comme stimulant dans la saison humide n’existe pas (Trans. Ent. Soc. Lond., 1902, p. 423), car la, la phase séche seule est connue a toutes les époques de année. Nous sommes par consé- quent conduits a Phypothése que le stimulant initiateur des change- ments aboutissant a un Papillon de la phase humide, peut étre fourni par eau déposée sur les feuilles de la plante nourriciére. La larve a pu ainsi l’avaler avec sa nourriture. Il est possible aussi que Vhumidité contenue dans les jeunes feuilles et les pousses qui ont ert activement apres la pluie agisse comme stimulant. Done Vhumidité sous une forme ou une autre est la seule condition associée a la saison humide que nous puissions concevoir comme absente ou relative- ment réduite sous ’ombre des foréts profondes. Je pense qu’il est par consequent probable que dans V’Artazia, — et sil en est ainsi chez cette espeéce, il en sera de méme pour beaucoup d’autres — Teau avalée avec la nourriture est le point de départ dune combinaison de chan- gements complexes. Ces derniers occasionnent une accélération dans le développement de Panimal et la production d’un Papillon beaucoup plus petit et plus leger. De fait ils produisent un inseete présentant tous les détails de forme, couleur et dessins caracteéristiques de la phase humide. Ceci n’est qu'une simple suggestion, mais je suis persuade qu'elle peut induire les naturalistes & méme d’étudier sur les lieux, 4 entre- prendre des expériences pour confirmer ou renverser cette hypotheése. Si les naturalistes peuvent étre ainsi amenés a observer, a penser et a expérimenter, nos spéculations seront abondamment justifiées, méme si elles se trouvent détruites par le mouvement critique qu’elles au- ront soulevé. Je ne puis conclure sans remercier vivement mon amie M'® Pe- tiljean pour son obligeance et les nombreux services qu’elle m/’a rendus en mettant ce bref mémoire en état d’étre publié. Si Pai obtenu quelque succes en exposant mes idées en langue francaise, je le dois presque entiérement a son aide. oo TYPOGKAPHIE FIRMIN-DIDOT ET C!°, — PARIS. Annales de LW SOHELE LIMOTIOLOGLG ILE LE LV OVAL. S 2S828, pric. eb scalps L. Hew. L, gidapler es de Afrigjite australe cl det Inde vA 2 ] 9 y 7 b22 7722. Z. Frecis almanal e 3. Frecis artaaita______- - SALSOR fii Z 2 a : ‘ eof THE PRESIDENT’S ADDRESS. AN ADDRESS ENTITLED “WHAT IS A SPECIES?” READ BEFORE THE ENTOMOLOGICAL SOCIETY OF LONDON AT THE ANNUAL MEELING ON THE 20rHh JANUARY, 1904. BY Pror. EDWARD B. POULTON, D.Se., M.A., Hon. LL.D. Princeron, F.R.S., HOPE PROFESSOR OF ZOOLOGY IN THE UNIVERSITY OF OXFORD, FELLOW OF JESUS COLLEGE, OXFORD, President of the Society. LONDON: PRINTED BY RICHARD CLAY AND SONS, LIMITED, LONDON AND BUNGAY. 1904. UR et: Lj Were, cae ee ine i} << ae “ui ; NF ~~ > % - THE PRESIDENTS ADDRESS. GENTLEMEN, It is a great pleasure to congratulate the Society at the close of another successful year. The repetition of this con- gratulation in successive Annual Addresses is happily almost monotonous. It is a monotony which will never weary us, and in itself an indication that no other monotony has prevailed. The meetings have been well attended, there have been numerous, varied, and interesting exhibits leading to animated discussions. Our Transactions do not reach the phenomenal dimensions attained in 1902, but still form a noble volume, containing 23 plates and well over 600 pages. There is a pleasing variety in the papers, and the domination of the Lepidoptera is less pronounced than usual. An important share of the space is occupied by memoirs on the Coleoptera, Hymenoptera, and Insect Bionomics, while the Diptera and Rhynchota are also represented. I should wish to refer again to the warmth of the greeting received as your President at a meeting of the Entomological Society of France on April 22nd. The cordial friendship between the followers of science in all lands is of happy augury for the advancement of the researches in which we find common aims and mutual sympathy and respect. On this, the first occasion on which I have the honour of addressng you formally, I cannot resist the temptation of ealling attention to a remarkable coincidence of a personal nature—the fact that the present occupant of this Chair and his immediate predecessor should be members not only of the same University, but of the same College, and that not a large one. When this fact was explained to a friend he said it was easily understood, because the study of natural history is infectious. This suggestion, plausible as it is, fails to account for the fact ; inasmuch as Canon Fowler left Jesus College, ( 6=) Oxford, in June 1873, while I did not matriculate until October of the same year, so that, as undergraduates, we never saw each other. Before speaking of the losses which have fallen so heavily upon our community during 1903,—the brother Fellows who have gone from our midst, I feel bound to allude to the grief which we share with the whole intellectual world at the passing away, towards the close of the old year, of the great thinker to whom we owe far more than we can realise. I well remember the sudden access of light received when, between the age of seventeen and eighteen, Herbert Spencer’s works were first placed in my hands. The whole of science seemed illuminated, the whole outlook broadened. It was the most sudden and by far the greatest intellectual awakening I have ever experienced. And, as we know well, it has been the same with thousands. After Shakespeare, no man has done more to bring together the English* of the Old World and the New. And not only among ourselves, but everywhere in the civilised world the writings of Herbert Spencer have stirred enthusiasm and compelled admiration, They have left strong, indelible, beneficent after-effects even in those who are unable to believe in the enduring stability of the Synthetic Philosophy—a fabric as fair and stately as any created by the mind of man. Since the above paragraph was written Mr. Herbert Spencer’s will has been made known in the Times for January 14th. I am sure that every Fellow of our Society keenly appreciates the expression of confidence which is implied in the gift which will hereafter be offered to us by the Trustees of the will to be so carried out as to secure the greatest possible advantage a gift which we shall regard as a solemn trust, to the science we serve. Freverick Bares, F.E.S., joined the Society as a ‘‘sub- seriber” in 1867. Subsequently withdrawing, he again entered the Society as a Fellow in 1897. He was born at Leicester in 1829, and his death occurred at Chiswick on the 6th of October, in his 74th year. Like his distinguished * For the justification of this use of the word see Sir Michael Foster's Presidential Address to Section D of the British Association at Toronto (Report for 1897), Ca) brother, H. W. Bates, F.R.S., he was especially devoted to the Coleoptera, although his interests were wide and embraced many aspects of natural history, both zoological and botanical. He was the author of many papers, chiefly dealing with the Heteromera, in our Transactions and in the ‘ Entomologist’s Monthly Magazine.” His exceedingly fine collection of Heteromera is now in the British Museum, while his collection of British Coleoptera was a gift to his intimate friend Mr. Horace Donisthorpe. Many friends mourn the loss of a keen and able naturalist, a many-sided and genial personality.* THe Rev. Joon Hocxine Hocxkine, M.A., J.P., F.ES., Rector of Copdock-with-Washbrook, near Ipswich, was elected a Fellow in 1896. His death occurred on the 10th of December last, at the age of 69. He was an ardent collector of the Lepidoptera, but having only recently joined the Society was unfortunately known to but few of the Fellows.t THe Rev. THomas AnseLL MarsuHatt, M.A., F.E.S., joined the Society in 1865. By his death on April 11, 1903, at Ajaccio, one of the few authorities upon the parasitic Hymen- optera is lost to science. Mr. Marshall was born at Keswick on March 18, 1827, the son of Thomas Marshall, an original member of the Entomological Society. He took a scholarship at Trinity College, Oxford, and passed through the Classical Honours course. With great powers asa linguist, and a student of Hebrew and Sanskrit, he worked for a time on the staff of the British Museum Library. Subsequently he took Holy Orders, and after engaging in scholastic work, held livings in various parts of England, interrupted only by his appoint- ment as Bishop’s chaplain in Antigua. In this island he was bereft of his wife, and was himself in serious danger from an attack of fever. Upon his return to England he was presented, in 1889, to the living of Botus Fleming, Cornwall, which he retained until 1897, when he retired to Corsica, and devoted the remainder of his life to his favourite science. T. A. Marshall’s earliest important work dealt with the Coleoptera (Journ. Linn. Soc. 1865). The first of the series of memoirs * See the Obituary notice in the ‘‘ Entomologist’s Record,” vol. xv, No. 12, by Horace Donisthorpe ; and that in the ‘‘ Entomologist’s Monthly Magazine,” Nov. 1903, p. 286. + See also the Obituary notice in the ‘‘Entomologist’s Monthly Magazine ” for Jan. 1904, p. 19. (8s) by which his name will be chiefly known was published in 1870, ‘‘Ichneumonidum Britannicorum Catalogus,” followed by the valuable monographs on the British Parasitic Hymen- optera, which appeared in the Transactions of this Society between 1872 and 1889. He published an important volume on a portion of the raconide in André’s “Species des Hyménoptéres d’Europe,” and was still at work on the subject at the time of his death. He was an accomplished draughts- man and a clear and admirable writer. The loss of so able a student of an important but much-neglected group will be long and deeply deplored.* Puinie Brookes Mason, M.R.C.S., F.L.S., F.E.S., a Fellow of our Society since 1874, died on November 6, 1903, at Burton-on-Trent. His death is a sad loss to his profession, to the neighbourhood in which he laboured, and to a wide circle of naturalist friends. Mr. Mason was born at Burton on January 2, 1842. After a medical education of unusual distinction and variety of valuable experience, he made his permanent home at his native town in the Midlands. The British fauna and flora formed the chief interest of his life, and he possessed magnificent collections of both. With his sympathetic genial nature, it was his delight to welcome his brother naturalists to share in the well-nigh unique advantages which he possessed. And as he was a skilled and honoured member of the healing profession, so he was ever ready to lend the weight of his influence and the power of his persuasion to promote peace and friendliness. As the Society concerned with the branch of natural history to which he was chiefly devoted, we recognise, with grief, that a strong influence for good has _ passed from us.+ Joun Sanpers Stevens, F.E.S., became a Fellow in 1862. His death at Woking, on July 15, makes a sad break in the ranks of the senior Fellows of the Society. * See also the Obituary notice in the ‘‘ Entomologist’s Monthly Maga- zine,” June 1903, p. 152, by R. McLachlan, F.R.S. ; and that in the ‘‘ Ento- mologist’s Record,” vol. xv, No. 7, p. 190, by G. C. Bignell. + See also the Obituary notice in the ‘‘Entomologist’s Monthly Magazine,” Jan. 1904, pp. 17, 18, by the Rev. Canon W. W. Fowler ; also “‘The Lancet” for Nov. 13, 1908. + See also the Obituary notice in the ‘‘Entomologist’s Monthly Maga- zine,”’ Sept. 1903, p. 229, Cn) Outside the number of our own Fellows, we miss four well- known names from the ranks of British entomologists :— Witiiam Duppa Crorcu, M.A., F.L.S., a keen student of the Lepidoptera, Coleoptera and Hemiptera; Epwarp Roperr Date, son of the eminent J. C. Dale, and himself an eager entomologist in his younger days; THz Very Rey. Canon Bernarp Smitu of Great Marlow, an enthusiastic collector and breeder of the British Lepidoptera ; Samurt James WILKINSON, author of the celebrated “British Tortrices,’’ published in 1859. We sympathise deeply with our brethren on the continent in their grief for the eminent men who have passed away in 1903 :—Jonannes Faust, the eminent authority upon the Curculionidx, whose collection contained over 13,000 species, of which more than 2000 were described by himself ; Pro- FESSOR AvuGustus RapciirreE Grote, A.M., the celebrated student of the Lepidoptera. “WHAT IS A SPECIES?” The late Professor Max Miiller, in an eloquent speech delivered at Reading in 1891, spoke of the necessity of examining, and, as time passes by, re-examining the meaning of words. He referred as an illustration to the man at the railway station who taps the wheels with his hammer, test- ing whether each still rings true or has undergone some change that may mean disaster. In almost the same way, the speaker maintained, a word may slowly and unobtrusively change its meaning, becoming, unless critically tested to ascertain whether it still 1ings true, a danger instead of an aid to clear thinking, a pitfall on the field of controversy. He then went on to say, that Darwin had written a great work upon the Origin of Species, and had never once explained what he meant by the word Species. So decided an utterance —the statement was made emphatically—ought to have in- volved a careful and critical search through the pages of the work that was attacked. However this may be, it is quite certain that the search was unsuccessful; and yet a few minutes’ investigation brought me to a passage in which the meaning attached by the author to the term Species is set PROC. ENT. SOC. LOND., v. 1903. G (0.28) down in the clear, calm, and simple language which did so much to convince an unwilling world. Darwin is speaking of the revolution which the acceptance of his views will bring about. “Systematists will be able to pursue their labours as at present; but they will not be incessantly haunted by the shadowy doubt whether this or that form be in essence a species. This, I feel sure, and I speak after experience, will be no slight relief. The endless disputes whether or not some fifty species of British brambles are true species will cease. Systematists will have only to decide (not that this will be easy) whether any form be suffici- ently constant and distinct from other forms to be capable of definition, and if definable, whether the differences be sufficiently important to deserve a specific name. This latter point will become a far more essential consideration than it is at present ; for differences, however slight, between any two forms, if not blended by intermediate gradations, are looked at by most naturalists as sufficient to raise both forms to the rank of species. Hereafter we shall be compelled to acknowledge that the only distinction between species and well-marked varieties is, that the latter are known, or believed, to be connected at the present day by intermediate gradations, whereas species were formerly thus connected. Hence, without quite rejecting the consideration of the present existence of intermediate grada- tions between any two forms, we shall be led to weigh more carefully, and to value higher, the actual amount of difference between them. It is quite possible that forms now generally acknowledged to be merely varieties may hereafter be thought worthy of specific names, as with the primrose and cowslip ; and in this case scientific and common language will come into accordance. In short, we shall have to treat species in the same manner as those naturalists treat genera, who admit that genera are merely artificial combinations made for con- venience. This may not be a cheering prospect, but we shall at least be freed from the vain search for the undiscovered and undiscoverable essence of the term species.” I have quoted from pages 484, 485 of the original edition (1859), and have italicised the sentences in which Darwin defines a species and distinguishes it from a variety. etl) Max Miiller’s special criticism falls to the ground, but his general exhortation remains, and I think we shall do well to be guided by it, and attempt to apply it to this difficult and elusive word SPECIES. The passage I have quoted was Darwin’s prediction of the meaning which would be attached to the word “species ”’ by the naturalist of the future. Nearly half-a-century has passed since those words were written. For more than a generation the central ideas of the “Origin” have been an essential part of the intellectual equipment, not only of every naturalist, but of every moderately intelligent man. What then is the meaning of the word “species” to-day, and how does it differ from that of the years before July 1, 1858, when the Darwin- Wallace conception of natural selection was first launched upon the world ? The present occasion is especially favourable for this inquiry, because we have just been given two additional volumes of the letters of Charles Darwin. After the three volumes published in 1887, naturalists were certainly unprepared for the welcome revelation of such a mine of wealth. The work is all the more valuable because it contains many letters from Alfred Russel Wallace and Sir Joseph Hooker, thus giving both sides of a part of their correspondence with Darwin. Then in 1900 the “ Life and Letters of Thomas Henry Huxley ”’ appeared, so that we are now admitted “ behind the veil,” and can read, as never before, the central thoughts of the great makers of biological history. On the publication of the last- named work, I took occasion to combat the view that the thousand closely-printed pages might have been reduced by omitting and condensing many of the letters. The serious student of those stirring years requires the opportunity of thinking over and comparing all the available thoughts and opinions of the chief actors in the memorable scene ; and the very repetition of certain ideas, which proves their persistence and dominance in the writer’s mind, is a matter of deep importance and interest. However it may be to the general reader, the student would deprecate the omission or condensa- tion of any of the writings of Darwin or Huxley. ‘The special interest and value in the letters of these men depend on the fact that their inmost convictions on matters of the deepest scientific importance are to be read, often in the compass of a brief sentence. There we find, as we cannot find in any other way, the real core of the matter, with all accessory and surrounding considerations stripped away from it.* A care- ful study of the two recent volumes of Darwin’s letters, and a re-study of the three earlier volumes, with a view to this Address, have shown how Darwin’s thoughts were again and again occupied upon subjects bound up with the problem I have ventured to bring before you this evening. The interest reaches its height when we find that strongly-marked differ- ences of opinion on fundamental questions are threshed out in the correspondence, when we see, as I shall have occasion to point out in greater detail in the later pages of this Address, Darwin differing sharply from Huxley on the one hand, and with Wallace on the other, as to the significance and history of sterility between species. In such episodes we are permitted to become the witnesses of a supremely interesting struggle, where the central figure of modern biological inquiry is contending with his chief comrades in the great fight,—with the co-discoverer of natural selection, with the warrior hero who stood in the forefront of the battle. The correspondence of Charles Darwin has a further deep interest for us. We see the means by which a gentle, sympathetic, intensely human nature overpassed the stern limits imposed by health, and was able to impart and to receive fresh ideas, and a stimulus ever renewed—the im- pulse to varied and unceasing research. I have lately been studying with keen interest the life of another great English- man, William John Burchell,} than whom no better equipped or more learned traveller ever explored large areas in two continents. When I state that searching inquiry has only brought to light a dozen of his letters, and that he was known to hardly any of the great naturalists of his day, we see the reason for the sad, unproductive, brooding close of a career which opened with almost unexampled brilliancy and * «Quarterly Review,” January 1901, p. 258. + ‘‘Ann. and Mag. Nat. Hist.,” January 1904, p. 45. gest =) promise. The time which we give to Societies such as this— time we are sometimes apt to grudge—is well spent. Here, and in kindred communities, a ‘‘man sharpeneth the counten- ance of his friend,” and there is born of the influence of mind upon mind thought which is not a mere resultant of diverse forces, but a new creation. The scientific man who shuts himself away from his fellow- men, in the belief that he is thereby obtaining conditions the most favourable for research, is grievously mistaken. Man, scientific man perhaps more inevitably than others, is a social animal, and the contrast between the lives of Darwin and Burchell shows us that friendly sympathy with our brother naturalists is an essential element in successful and continued investigation. I do not suppose that it is necessary to justify a discussion of the term “species” as the subject of the Anniversary Address to the Entomological Society of London, The students of insect form and function hold an exalted place among naturalists. The material of their researches enables them, almost compels them, to take the keenest and most active interest in broad questions affecting the history and course of life on our planet. Naturalists engaged upon other groups may reasonably inquire why insects, above all other animals, should be so especially valuable for the elucidation of the larger problems which deal, not only with the species of a single group, but with every one of the innumerable and infinitely varied forms, vegetable no less than animal, in which life manifests itself. The answer is to be found in the large number of offspring produced by each pair of insects, and the rapidity with which the generations succeed each other, many cycles being completed in a single year in warm countries; in the severity of the struggle for life which prevents this remarkable rate of multiplication from becom- ing the cause of any progressive increase in the number of individuals; and finally, in the character of the struggle itself, which is precisely of that highly specialised kind between the keen senses and activities of enemies, and the means of concealment or other modes of defence of their insect prey, which leads, by action and answering reaction, to ( 4) a progressive raising of the standard in both pursuer and pursued. This is why it is that insects mean so much to the naturalist or to the philosopher who desires to look beneath the surface for the forces which have moulded existing forms of life out of earlier and very different forms. The wings of butterflies, it has been said, serve as a tablet on which Nature writes the story of the modification of species.* But the careful study of insects tells us even more than this; for it gives us the clearest insight we as yet possess into the forces by which these changes have been brought about. Light is thrown upon the causes to which organic evolution is due no less than upon the course which organic evolution has pursued. + And I think we shall find that a consideration of the numerous distinct categories of forms presented by the insect world is especially advantageous in an attack upon the difficult question—‘‘ What is a species?”, while properly-directed observation of insects, and experiments upon insects afford the most hopeful prospect of a final answer. And here I am compelled to say a word in defence of the Lepidoptera from this point of view. Undoubtedly it is most unfortunate that the obvious attractions of the group have led entomologists to neglect other Orders ; for this can be the only explanation why naturalists have so often preferred to do over again what others have done already, apparently oblivious of fields comparatively empty and unexplored. It must further be admitted, that the greater visibility of structure, and the more urgent necessity for the study of structure in other groups, render them better instruments of zoological education. But although the Lepidoptera are inferior in this respect, although they lack the unique interest of the Hymenoptera and the social Neuroptera, and can- not claim any of the respect due to venerable age like the Aptera, Orthoptera and Neuroptera—in spite of their many demerits they stand at the head, not only of all insects, but * H. W. Bates, quoted by A. R. Wallace in ‘‘ Natural Selection,” London, 1875, p. 132. The original passage may be found in ‘‘ The Naturalist on the Amazons” (London, pp. 347, 348 of the 1879 edition). + This justification for the study of insects was urged by the present writer in the Hope Reports, vol. iii, 1903, preface, pp. 4, 5. Cp?) of the whole organic world, as the registers of subtle and elusive change—ever going on, yet never seen,—by means of which forms are slowly becoming different from what they have been in the past. It is the existence of a complex pattern composed of several colours, which renders butterflies and to a less extent moths such a remarkably delicate record of change. As we trace the representative individuals of a community of butterflies over any wide range, the trained eye, and often the inexperienced eye, can detect differences which are not seen to anything like the same extent in the individuals of other Orders with corresponding ranges. If the wings of Hymenoptera, Diptera, or Orthoptera possessed the same elaborate patterns as the Lepidoptera, we cannot doubt that they too would exhibit the same differences in various parts of their areas. These continual changes which we find as we study the distribution of Lepidopterous forms in space, is undoubtedly a measure of the speed with which they have occurred in time. Rapidity of change is essential if it is to keep its adjustment with nicety to the fleeting details of distribution.* Hence we may confidently believe, that if we * It is to be observed that I speak of the details as fleeting. The general area of distribution is doubtless extremely ancient in most cases. Thus, although a species of Heliconius, etc., may have originated within the South American tropics, and never have wandered beyond them, the complex shape of its actual area of distribution at any one time cannot be regarded as fixed or ancient. Yet in many a species the variation of the constituent individuals is adjusted with precision to the geographical details of the existing range. Mr. Roland Trimen, on reading the above footnote, writes to me January 24, 1904:—‘‘ Your note reminds me of the recent appearance on the Natal coast of several conspicuous East-African butterflies, vid. : Pieris spilleri, Crenis rosa, and Godartia wakefieldii, all of which are shown to have not only extended their range to a point where they were previously quite unknown, but to have also established themselves in the fresh area. This is a good case, as Durban has had, for the last twenty- five years at least, a number of keen collectors of Lepidoptera, whom such conspicuous forms could not possibly have escaped had they inhabited the neighbourhood. Besides these species, the last butterfly that my friend and collaborator, the late Colonel Bowker, sent to me (1898) was the large and extremely conspicuous black-and-white Acrwa satis, which he took at Malvern, near Durban. This is the only example known to me to have occurred in Natal ; but Bowker, who noted the resemblance on the wing to Papilio morania, wrote that he had seen one other for certain, and thought that he might very possibly have passed over more examples for the common Papilio named. This last case is of special interest (should it prove one of extended range like the three mentioned), because the Acree are so exceptionally slow-flying and gregarious, that they must spread very slowly indeed into fresh areas.” ( 16 ) could wake up in say a thousand years, we should be able to detect changes in the patterns of some butterflies. Although I am afraid the advance of science is not likely to be sufficiently rapid in our time for me to hold out any prospect of such an experience for any of you, there is every reason why we should afford this opportunity to posterity. A critical examination of the fragments of many species of butterflies captured ninety years ago by Burchell in 8. Africa, and gnawed to pieces during his Brazilian travels from 1825 to 1830, renders it probable, nay, almost certain, that with moderate care, insect pigments will endure for an indefinite period in our museums. One important justification for the great and permanent outlay required to bring together and maintain large collec- tions of insects is, that we are allowing our successors the chance of detecting and measuring the rate of specific change.* And, as I have already said, for this purpose the Lepidoptera stand pre-eminent. For the purpose of the inquiry this evening, our instances will be drawn from the Lepidoptera rather than other Orders of insects, because of the numberless examples of subtle distinction between forms which but yesterday, so to speak, became separate ; because of our knowledge, insufficient but considerable, of their geographical ranges; because of our experience, excessively imperfect and scanty, but still much larger than in other Orders, of inter-breeding and of descent from parent to offspring. First among the attempts to define species must be placed that which we rightly associate with the name of Linnzus. It has been admirably pointed out by the late Rev. Aubrey L. Moore, + that the dogma of the fixity of species is entitled to none of the respect which is due to age. “It is hardly credible to us,” he wrote, “that Lord Bacon, ‘the father of * Karl Jordan argues with great force in favour of specialisation in this direction by our museums. (See ‘“‘ Novitates Zoologice,” vol. iii, December 1896, pp. 431-433.) The Burchell collection from Brazil is only seventy-four to seventy-nine years old, but the species are numerous, and often represented by long series. An account of the butterflies by Miss Cora B. Sanders will shortly appear in the ‘‘ Annals and Magazine of Natural History” ; and it will then be seen that the evidence of change in certain forms is by no means wanting. + ‘Science and the Faith,” London, 1889, pp. 174 e¢ seq. Car) modern science’ as he is called, though he was only a school- man touched with empiricism, believed not only that one species might pass into another, but that it was a matter of chance what the transmutation would be. Sometimes the medieval notion of vivification from putrefaction is appealed to, as where he explains the reason why oak boughs put into the earth send forth wild vines, ‘which, if it be true (no doubt), he says,* ‘it is not the oak that turneth into a vine, but the oak bough, putrefying, qualifieth the earth to put forth a vine of itself... Sometimes he suggests a reason which implies a kind of law, as when he thinks that the stump of a beech tree when cut down will ‘ put forth birch,’ because it is a ‘tree of a smaller kind which needeth less nourishment.’ t Elsewhere he suggests the experiment of polling a willow to see what it will turn into, he himself having seen one which had a bracken fern growing out of it!{ And he takes it as probable, though it is inter magnalia nature, that ‘ whatever creature having life is generated without seed, that creature will change out of one species into another.’ Bacon looks upon the seed as a restraining power, limiting a variation which, in spontaneous generations, is practically infinite, ‘for it isthe seed, and the nature of it, which locketh and boundeth in the creature that it doth not expatiate.’” And the author also shows that much earlier than the date at which Bacon wrote, theologians were by no means unanimous in accepting “ special creation ” ; that St. Augustine even distinctly rejected it, and propounded an idea which was evidently considered tenable by the greatest of the schoolmen, St. Thomas Aquinas. St. Thomas’ words, quoted by Mr. Aubrey Moore, are as follows :—‘“ As to the production of plants, Augustine holds a different view. For some expositors say that, on this third day (of creation), plants were actually produced each in his kind—a view which is favoured by a superficial reading of the letter of Scripture. But Augustine says that the earth is then said to have brought forth grass and trees causaliter— i.e. it then received the power to produce them.” § * ‘Nat. Hist.” Cent. vi, 522, fol. ed. - + L.c. p. 523. de Capa) las § St. Thomas Aquinas, ‘‘Summa Theol.” Prima Pars. Quaest., isatre- Art. 2. PROC. ENT. SOC. LOND., v. 1903. H ( 18) How then did the fixity of species become an article of belief in later years? Aubrey Moore traces it to the influence of Milton’s account of creation in the seventh book of “Paradise Lost” (1. 414, e¢ seg.), and Professor Huxley had still earlier suggested the same cause in his ‘‘ American Addresses.” I cannot help thinking that the belief had even more to do with the spirit of the age which spoke, and spoke for all time, with Milton for its interpreter,—the spirit of the Puritan movement, with its insistence on literal interpreta- tion and verbal inspiration. John Ray was Milton’s younger contemporary, and many writers, including Aubrey Moore, have thought that with him began the idea of the fixity of species. Sir William Thiselton Dyer has, however, recently pointed out, that a conception similar to Ray’s may be traced to Kaspar Bauhin (1550-1624) and to Jung (1587-1657).* From Ray we pass to Linneus with his often quoted definition, “Species tot sunt, quot diversas formas ab initio produxit Infinitum Ens, quae formae, secundum generationis inditas leges produxere plures, at sibi semper similes.” Of the Ray-Linnzeus-Cuvier conception of species which found its most precise and authoritative expression in the above-quoted latin sentence, Dr. F. A. Dixey has well said that it ‘‘ left order where it found confusion, but in substituting exactness of definition for the vague conceptions of a former age, it did much to obscure the rudimentary notions of organic evolution which had influenced naturalists and philosophers from Aristotle downwards.” + At the same time it is by no means improbable, as Dixey has suggested, that the Linnean concep- tion “of the reality and fixity of species perhaps marks a necessary stage in the progress of scientific enquiry.” t The Linnean idea of special creation has no place in the realm of science ; it is a theological dogma. The formation of species, said Darwin in a letter to Lyell, “has hitherto been viewed as beyond law; in fact, this branch of science * ««The Edinburgh Review,’ Oct. 1902, p. 370. + ‘‘Nature,” June 19, 1902, p. 169. For the history of these early ideas upon evolution see ‘‘ From the Greeks to Darwin,” by H. F. Osborn, New York, 1894. + ‘*Church Quarterly Review,” Oct. 1902, Art. II p. 28. (ee) is still with most people under its theological phase of develop- ment.” * And this explains the intense opposition at first encountered by the principles of the “ Origin.”” The naturalist whose genius sympathised most fully with the Linnean con- ception would feel that he was admitted, like a seer of old, into the presence of the Maker of the Universe. His convictions as to species were to him more than the conclu- sions of the naturalist; they were a revelation, stirring him to “break forth and prophesy.” Do we not sometimes recognise a lingering trace of this phase of thought in the serious shake of the head and tone of profound inner conviction with which we are sometimes told that the speaker is decidedly of the opinion that so-and-so is a perfectly good species ? We recognise the same sharp antagonism between two irreconcilable sets of ideas when the late W. C. Hewitson expressed such horror at Roland Trimen’s remarkable dis- covery of the polymorphic mimetic females of the Papilio merope group. The wonderfully acute detection of minute but significant resemblance hidden under the widest possible superficial difference, which enabled the great South African naturalist to unravel the tangled relationships, was to Hewitson but one of ‘‘ the childish guesses of the . . . Darwinian School.” To meet the carefully-thought-out argument, the only objec- tions that could be urged were that the conclusion stretched too severely the imagination of the writer, and that it shocked his notion of propriety ! 7 * Letter 132 to C. Lyell, Aug. 21, 1861. ‘‘More Letters of Charles Darwin,” London, 1903, i, p. 194. + See an account of the controversy in Trans. Ent. Soc. Lond., 1874, p. 137. The passages I have alluded to are as follows:—‘‘ P. merope, of Madagascar, has a female the exact image of itself; and it would require a stretch of the imagination, of which I am incapable, to believe that the P. merope of the mainland, having no specific difference, indulges in a whole harem of females, differing as widely from it as any species in the genus. .. . In the two species of Papilio which have lately been united, Torquatus and Candius, and Argentus and Torquatinus, though much unlike each other, there is quite sufficient resemblance not to shock one’s notions of propriety.” A little later Mr. Hewitson himself received evidence of the truth of the conclusion he so disliked ; for he told how his collector Rogers had sent ‘‘ Papilio merope and P. hippocoon, taken by him in copulation, another illustration of the saying that ‘truth is stranger than fiction.’ I find it very difficult (even with this evidence) to believe that a butterfly, which, when a resident in Madagascar, has a female the image of itself, should, in West Africa, have one without any resemblance to it at all” (‘* Entomologist’s Monthly Magazine,” Oct. 1874, p. 113). ( 20 ) Tn leaving the dogma of ‘special creation,” and the assump- tion of “ fixity of species” with which it is bound up, it is only right to point out how completely the logical foundations of both were undermined by the great thinker who has just passed away. Years before the appearance of the Darwin- Wallace essay, and of the “Origin,” Herbert Spencer wrote on “The Development Hypothesis.” * Although of course wanting the great motive power to evolution supplied by natural selection, this essay is a powerful and convincing argument for evolution as against special creation. It is astonishing that it did not produce more effect. I may appro- priately conclude this section of the Address by quoting the results of Herbert Spencer’s critical examination, from every point of view, of the Linnean conception of species. “ Thus, however regarded, the hypothesis of special creations turns out to be worthless—worthless by its derivation ; worthless in its intrinsic incoherence; worthless as absolutely without evidence; worthless as not supplying an intellectual need ; worthless as not satisfying a moral want.” t If then the Linnean conception of species—separately created and fixed for all time at their creation—has been abandoned, what have we to put in itsplace? Ina letter to Hooker, Dee. 24, 1856, Darwin gave a list of the various definitions he had met with. “TI have just been comparing definitions of species, and stating briefly how systematic naturalists work out their subjects. . . . It is really laughable to see what different ideas are prominent in various naturalists’ minds when they speak of ‘species’; in some, resemblance is everything, and descent of little weight—in some, resemblance seems to go for nothing, and creation the reigning idea—in some, descent is the key—in some, sterility an unfailing test, with others it is not worth a farthing. It all comes, I believe, from trying to define the indefinable.” { As regards the work done by the systematist, we find that Darwin did not agree with those of his friends who thought * In the Leader, between January 1852 and May 1854, reprinted in ‘Essays Scientific, Political, and Speculative.” London, 1868, vol. i, Pp. 377. + ‘*The Principles of Biology.”” London, 1864, vol. i, p. 345. + “Life and Letters of Charles Darwin,” London, 1887, vol. ii, p. 88. that a belief in evolution would entirely alter its character. Thus he wrote to Hooker, Sept. 25, 1853 :—“In my own work I have not felt conscious that disbelieving in the mere permanence of species has made much difference one way or the other ; in some few cases (if publishing avowedly on the doctrine of non-permanence) I should mot have affixed names, and in some few cases should have affixed names to remark- able varieties. Certainly I have felt it humiliating, discussing and doubting, and examining over and over again, when in my own mind the only doubt has been whether the form varied to-day or yesterday (not to put too fine a point on it, as Snagsby would say). After describing a set of forms as distinct species, tearing up my MS., and making them one species, tearing that up and making them separate, and then making them one again (which has happened to me), I have enashed my teeth, cursed species, and asked what sin I had committed to be so punished. But I must confess that perhaps nearly the same thing would have happened to me on any scheme of work.” * The essentially subjective character of the results reached by the systematist stands out with remarkable force in this as in other passages of Darwin’s letters. A few years later, on July 30, 1856, he wrote to the same friend :—‘‘I differ from him [Lyell] greatly in thinking that those who believe that species are not fixed will multiply specific names: I know in my own case my most frequent source of doubt was whether others would not think this or that was a God-created Barnacle, and surely deserved a name. Otherwise I should only have thought whether the amount of difference and permanence was sufficient to justify a name.” 7 Disregarding for the moment the term species, it is convenient to consider the various groupings of individual animals and plants. 1. Forms having certain structural characters in common distinguishing them from the forms of other groups. Groups thus defined by Diagnosis may be conveniently called Syndia- gnostic (cvv, together ; didyvwors, distinction). * ‘Life and Letters,” vol. ii, p. 40. + Ibid. vol. ii, p. 81. ( 22.) 2. Forms found together in certain geographical areas and not in other areas. Such groups may be called Sympatrie (ovv, together ; zatpa, native country). The occurrence of forms together may be termed Sympatry, and the discontinuous distribution of similar forms Asympatry. 3. Forms which freely inter-breed together. These may be conveniently called Syngamic. (cvv, together; ydpos, marriage). Free inter-breeding under natural conditions may be termed Syngamy; its cessation or absence, Asyngamy (equivalent to the Amixia of Weismann). 4. Forms which have been shown by human observation to be descended from common ancestors. Such groups may be called Synepigonic (cvv, together; éiyovos, descendant). Breed- ing from common parents may be spoken of as Lpigony or the production of Epigonic evidence.* My friend, Professor E. Ray Lankester, to whom I owe -so much, in this as in many other subjects, is inclined to think that we should discard the word species not merely momentarily but altogether. Modern zoology having aban- doned Linnzeus’ conception of “species” should, he considers, abandon the use of the word. In his opinion the “ origin” of species was really the abolition of species, and zoologists should now be content to describe, name, draw, and catalogue Jorms. Furthermore, the various groups of forms _ briefly defined above should be separately and distinctly treated by the zoologist, without confusion or inference from one to the other. The systematist should say, “I describe and name certain forms a, 6, etc.”; and then he or another may write a separate chapter, as it were :—“‘I now show that the forms ab, ac, ad (form names) are syngamic:” at another time he may give reason for regarding any of them as related by epigony. I fear that this suggestion is a ‘counsel of perfection,” impossible of attainment, although there would be many * My friend Mr. Arthur Sidgwick has kindly helped me by suggesting the appropriate Greek words. The use of éx/yoves I owe to my friends Mr. Arthur Evans and Mr. R. W. Macan. ‘The adjectival termination is made -ic throughout for the sake of convenience, although Sympatriote or Sympatrid would have been more correct. ( 23) and great advantages in thus making a fresh start and in the abandonment of ‘species,’ or the restriction of the word to the only meaning it originally possessed before it was borrowed from logic to become a technical term in zoology.* Professor Lankester in former years published (I cannot at this moment lay my hands upon the communication) the suggestion that the term species should be limited to a group which includes all the forms derived from common ancestors within human experience, or inferred to be so derived within the possible period of human observation. Thus if the common ancestry of two forms has to be traced back to a period be- yond the late pre-historic times (or beyond any other arbi- trary line which is agreed upon), then they are not members of the same species. Professor Lankester is the first to admit that the practical application of this as of every other con- ception of species would very often mean a great deal more than we can pxove, in fact, hypothesis. It is evident too that Darwin regarded persistence of form as an important criterion of aspecies. We recognise this in the definition I have quoted from the “Origin” (see p. 10), and it is stated with even greater force in the following passage, where persistence is placed beside other distinguishing marks of aspecies and given the pre-eminence. In a letter to Hooker (October 22, 1864) Darwin says :—‘‘I will fight to the death that as primrose and cowslip are different in appearance (not to mention odour, habitat, and range), and as I can now show that, when they cross, the intermediate offspring are sterile like ordinary hybrids, they must be called as good species as aman anda gorilla. The power of remaining for a good long period constant I look at as the essence of a species, combined with an appreciable amount of difference.” T It is now necessary to examine in some detail the most usual conception of a species, a conception based upon distinguishing structural characters, or diagnosis. This idea of a species is clearly expressed by Sir William Thiselton Dyer, when he speaks of the older writers who oy Ska) dip dale Dixey i in ‘‘ Nature,” June 19, 1902, p. 169. + ‘‘More Letters,” vol. i, p. 252, Letter 179. ( 24) employed “the word species as a designation for the totality of individuals differing from all others by marks or characters which experience showed to be reasonably constant and trustworthy, as is the practice of modern naturalists.” * This conception of a species is founded upon transition. Whenever a set of individuals can be arranged, according to the characters fixed upon by the systematist, in a series without marked breaks, that set is regarded as a species. The two ends of the series may differ immensely, may diverge far more widely than the series itself does from other series; but the gradual transition proclaims it a single species. If transitions were all equally perfect of course there would be no difficulty. But transitions are infinite in their variety ; while the subjective element is obviously dominant in the selection of gaps just wide enough to constitute interspecific breaks, just narrow enough to fuse the species separated by some other writer,—dominant also in the choice of the specific characters themselves.t Looking back upon the interval between Linnzeus and Darwin, it seems remarkable that the mutability of species was not forced upon systematists as the result of their own labours. It is astonishing that many a naturalist was not driven by his descriptive work to the conclusion which Darwin stated to Asa Gray on July 20, 1856: ‘“‘— as an honest man, I must tell you that I have come to the heterodox conclusion, that there are no such things as independently created species—that species are only strongly defined varieties.” { For, as I have said above, every describer of species made continuity and transition in characters the test of a variety, discontinuity the test of a separate species. And in diflicult cases no two of them agreed in their conclusions. Many passages in Darwin’s correspondence convincingly prove how essential an element is this continuity, and how inevitable * Le. p. 870. + How important this choice may be is well shown by Karl Jordan in ‘*Novitates Zoologice,” vol. iii, Dec. 1896, pp. 428-480. Characters are subject to independent variation as well as correlated variation. Hence there may be the widest discrepancy between the transitions constructed by naturalists making use of different characters. + ‘‘Life and Letters,” vol. ii, p. 79. ( 25) is the dominance of the subjective element. Thus he writes about his descriptive work on Cirrhipedes to Hooker, October 12, 1849 :—‘T have of late been at work at mere species describing, which is much more difficult than I expected, and has much the same sort of interest as a puzzle has; but I confess I often feel wearied with the work, and cannot help sometimes asking myself what is the good of spending a week or fortnight in ascertaining that certain just perceptible differences blend together, and constitute varieties and not species. As long as Iam on anatomy I never feel myself in that disgusting, horrid, ewt bono, inquiring humour.” * On another occasion, when Darwin was anxious to ascertain the ‘‘ close species” in the North American Flora, and wrote for information to Asa Gray, he frankly adopted the sub- jective criterion in order to explain exactly what he meant. He wrote, June 8, [1855]:—“The definition I should give of a ‘close species’ was one that you thought specifically dis- tinct, but which you could conceive some other good botanist might think only a race or variety ; or, again, a species that you had trouble, though having opportunities of knowing it well, in discriminating from some other species.” t Asa Gray’s reply is also very interesting from the same point of view. He-wrote, June 30, 1855 :—“‘Those thus connected” [he had bracketed the “close species” in a list of the Flora], “ some of them, I should in revision unite under one, many more Dr. Hooker would unite, and for the rest it would not be extraordinary if, in any case, the discovery of intermediate forms compelled their union.” { Darwin was evidently in high spirits when he wrote the following passage which bears on the same subject. The “Origin”? had been published on November 24, 1859, and the whole edition of 1250 copies sold on the day of issue. On November 29 he wrote to Asa Gray :—‘ You speak of species not having any material base to rest on, but is this any greater hardship than deciding what deserves to be called a variety, and be designated by a Greek letter? When I * © Tife and Letters,” vol. i, p. 379. + Ibid., vol. ii, p. 64. ~ “More Letters,” vol. i, p. 421, Letter 324. (26) was at systematic work I know I longed to have no other difficulty (great enough) than deciding whether the form was distinct enough to deserve a name, and not to be haunted with undefined and unanswerable questions whether it was a true species. What a jump it is from a well-marked variety, pro- duced by natural cause, to a species produced by the separate act of the hand of God! But I am running on foolishly. By the way, I met the other day Phillips, the paleontologist, and he asked me, ‘ How do you define a species?’ I answered, ‘IT cannot.’ Whereupon he said, ‘ At last I have found out the only. true definition—any form which has ever had a specific name !’”’ * The idea of a species as an inter-breeding community, as syngamic, is, I believe, the more or less acknowledged found- ation of the importance given to transition. This will become clearer from the consideration of a concrete example. The common black-and-white Danaine butterfly, Amauris niavius of West Africa, is represented on the East and South-East Coasts by a very similar butterfly, distinguished by the greater size of the largest white patch, and of the white spot in the cell of the fore-wing. Both forms are very constant in the areas over which they were known, and on these constant easily recognisable characters the eastern butterfly was described as a distinct species under the name of A. domint- canus. Aurivillius, however, in his valuable Catalogue refuses to recognise this latter as a distinct species, and considers it as the dominicanus variety of niavius. Through the kind- ness of Mr. C. A. Wiggins and Mr. A. H. Harrison, the Hope Department has recently been presented with an exceedingly fine series of butterflies from both east and west of the northern shores of Lake Victoria Nyanza. These have been carefully studied by Mr. 8S. A. Neave, B.A., of Magdalen College, Oxford, who finds that the typical niavivs occurs in great abundance to the west of the lake, while on the east he meets, in both collections, with varieties beautifully inter- mediate between it and dominicanus. These varieties, occurring precisely in the zone where the eastern form meets the western, complete for the systematist the transition which * “* More Letters,” vol. i, p. 127, Letter 79. iw) (7) renders dominicanus a variety of niavius and not a distinct species. But it is clear that they do more than this; they make it almost certain that the two forms freely interbreed, and constitute but a single syngamic community. This is one of the remarkably clear examples. In many cases we know the transition, but the extremes are not sorted out in different parts of the total area of distribution. Never- theless if complete enough the transition of forms on the same area always raises the strong presumption that we are dealing with a syngamic community. Probably the most remarkable series of transitional varieties ever depicted is that shown in the eleven quarto plates of the last part of Monsieur Charles Oberthiir’s great “ Etudes d’Entomologie,” entitled “ Variation des Heliconia thelxiope et vesta”” (Rennes, February, 1902). The method of diagnosis, at its clearest and simplest, is always consistent with, and often strongly suggests, an under- lying syngamy. There are, however, numberless examples belonging to various categories in which a rigid adherence to diagnosis cannot avail. In these cases the systematist frankly appeals to syngamy or synepigony as decisive; and if he has not direct proof of the existence of either of these, indirect evidence is, at any rate provisionally, regarded as sufficient. I. Dimorphism, Polymorphism :—In an_ ever-increasing number of examples an assemblage of individuals is regarded as a single species, although split up into two or more widely different and sharply separated groups, between which transi- tional varieties are excessively rare or even unknown. For instance, the extremely abundant, widely distributed butterfly Limnas chrysippus includes among other forms one in which the black-and-white tip is wanting from the fore-wing, the dorippus (=klugii) form. This variety is sharply cut off from the type fcrm. Although faint traces of a former white bar can be made out in dorippus, I have never seen, among thousands of individuals, the material out of which a good transitional series between it and chrysippus could be con- structed. In this case the evidence of syngamy is strong and complete ; for Col. Yerbury has recorded the fact that the two forms certainly oceur in copuld.* But if this evidence were wanting there would still be strong presumptive evi- dence that the forms are associated by syngamy and synepigony. Thus, so far as our knowledge extends, dorippus occurs as the only form in certain parts of N.E. Africa alone. From this, its metropolis, dorippus spreads on all sides, its individuals existing intermingled with those of chrysippus, becoming less and less numerous until they finally die out. Thus if we trace the two forms eastward we find them both abundant at Aden; further east, at Karachi, dorippus is well known, but very scarce as compared with chrysippus; in Southern India it is a great rarity, if indeed it is known at all on the mainland ; in Ceylon a single specimen was captured by Col. Yerbury in 1891, and since then others have been taken.T Further east I have never heard of a specimen. Similarly when it is traced southward in Africa, dorippus is dominant in the coast strip of British East Africa, where it constitutes about three-quarters of the total number of individuals. Further to the south it becomes rarer and rarer, until in Natal and the Cape, if it occurs at all, it is even rarer than in Ceylon.t Such a distribution is consistent with the inter- pretation that dorippus and chrysippus are two forms in one syngamic community. It is difficult on any other hypothesis to account for the facts which we observe on the outskirts of * Speaking of his experience at Aden, Col. Yerbury says: ‘‘I have taken them [the forms of chrysippus] in coitu in every possible com- bination.” (Journ. Bomb., Nat. Hist. Soc., vii. (1892), p. 209.) + See Major N. Manders, F.Z.S., in Journ. Bomb. Nat. Hist. Soe., xiv (1902), p. 716 :— 7 *‘The first specimen of this insect [dorippus=klugii] in Ceylon was captured by Lieut.-Colonel Yerbury at Trincomalis, April 15th, 1891. . .” Of five or six more recent examples Major Manders writes, ‘“‘ These speci- mens were captured by Mr, Pole at Puttalam on the east coast and Ham- bantotte on the south coast in the dryest and perhaps most arid portion of the island. It is evidently widely distributed in the desert portion of the island and is possibly not uncommon.” ‘The distribution of this insect in India cannot yet be fully known ; it is rare in Canara, but is not yet reported from the plains of the Deccan, or Southern India, so far as I am aware, though it probably exists.” The occurrence of dorippus at Bombay, Kutch, and Sind had been previously published by Major Manders and ‘the late Mr. de Nicéville in Journ. As. Soc. Bengal, vol. Ixviii, Pt. ii, No. 3, 1899, p. 170. + Mr. Roland Trimen tells me that he knows of only three South- African dorippus :—two from Durban and one from Pretoria. The latter and one of the former were taken by Mr. W. L. Distant (Ann. Mag. Nat. Hist. (7), vol. i, 1898, pp. 48, 49). ( 29) the range of dorippus—the occasional appearance of single individuals in the swarms of the type form. And if the two are syngamic on the outskirts, the gradual transition in pro- portions towards the metropolis of dorippus suggests that they are syngamic throughout. Common as the species is— probably the commonest butterfly in the world,—the evidence from epigony has never been obtained, although from the point of view of heredity the investigation promises to be of the deepest interest. The remarkable forms of the females of the Papilio merope group already alluded to afford another excellent example, although in this case good transitional series can be constructed. The evidence of syngamy was first obtained by Hewitson (see p. 19), but is now wellknown. The evidence of epigony has fortunately been obtained in 1902 and again within the last few weeks by one of our Fellows at Durban, Mr. G. F. Leigh. Eggs from a female of the commonest cenew form yielded a synepigonic group, including a large majority of forms like the parent, but also examples of the very different Aippocoon form. Still more recently seven eggs from the rarest of the forms, trophonius, produced, in addition to males, two females of the cenea variety, and not one resembling the parent. These differences, although only of colour and pattern, greatly exceed those between ordinary close species. When we deal with other kinds of dimorphism or polymorphism involv- ing important structural differences, such as those of the social Hymenoptera and Neuroptera, the discriminating characters between nearly related genera are commonly equalled or exceeded. IL. Seasonal Dimorphism :—In certain exceedingly interest- ing examples of dimorphism the relation between the forms is epigonic and not syngamic ; for rare and occasional inter-breed- ing is not syngamy. I refer to the most strongly-marked cases of seasonal dimorphism in butterflies, especially the wonderful examples proved to be epigonic by Guy A. K. Marshall. In some of the forms the two seasonal phases were not even regarded as closely related species. In these extraordinary cases, where the widest difference in colour and pattern exists, in combination with others which are far more deep-seated, ( 30.) I urged upon Mr. Marshall that the few recorded examples of capture or observation 77 coitw were insufficient evidence of specific identity, and that nothing short of epigony would suffice. In seasonal dimorphism, in the dimorphism of social insects, and doubtless in a large proportion of other examples, it is probable, indeed often certain, that the different forms are produced in response to some stimulus which acts at a speci- ally susceptible period of the life-history ; but from the point of view of the systematist the mature individuals can only be known as forms which, structurally widely different, must nevertheless be placed within the limits of a single species. The investigation of the probable physiological causes of differ- ence is, however, of the utmost importance from other points of view. Altogether apart from its bearing upon dimorphism, the effect of individual susceptibility to stimulus requires treatment in a separate category. IU. Individual Modijication : *—One of the most striking developments of recent years has been the growth in the number of these very cases in which an individual animal or plant has been rendered by natural selection susceptible to some stimulus associated with each one of its possible normal environments. Every individual of such _ species comes into the world with two or more very distinct and very different possibilities before it, each of which will be realised only in the appropriate environment—realised as the response to some stimulus provided by the environment itself. We can see clearly that this idea was in Darwin’s mind, although there were then but few facts which pointed in its direction. Thus in Schmankewitsch’s experiments Crustacea of the species Artemia salina were described as gradually changing in the course of generations, as the result of a progressive freshening of the water in which they were kept, until they took on the characters of the genus Bran- chipus. On this subject Darwin wrote to Karl Semper, February 6, 1881 :—‘* When I read imperfectly some years * “A structural change wrought during the individual's lifetime (or acquired), in contradistinction from variation, which is of germinal origin (or congenital).” Dict. of Phil. and Psych., ed. by J. Mark Baldwin, New York and London, vol. ii, 1902, p. 94. C31") ago the original paper, I could not avoid thinking that some special explanation would hereafter be found for so curious a case. I speculated whether a species very liable to repeated and great changes of conditions might not assume a fluctuating condition ready to be adapted to either conditions.” * I venture to express the prediction that this class of cases, already very numerous, will hereafter be immensely enlarged, and will become especially important in the vegetable king- dom.+ Although Hooker at one time took the opposite side, and thought that plants were never ‘‘changed materially by external conditions—except in such a coarse way as stunting or enlarging,” { Darwin considered that “ physical conditions have a more direct effect on plants than on animals.” § Un- doubtedly the view at the time was that of Buffon, the idea of an operation of the environing forces almost as direct as those which produce the weathering of rocks or the whitening of an exposed flint. But it is probable that the more in- timately we know of the conditions of plant-life, the more fully it will be recognised that all such changes are adaptive. * ¢¢ More Letters,” vol. i, p. 391, Letter 303. + See ‘‘Stimulus and Mechanism as Factors in Organisation” by J. Bretlend Farmer, F.R.S. (the New Phytologist, vol. ii, Nos. 9 and 10 Novy. and Dee. 1903), Professor Farmer speaks of the probable prevalance in the plant-world of ‘‘a constant specific mechanism that is able to be actuated in different ways by different kinds of stimuli.” Although for the purpose of his paper Professor Farmer is concerned with the train of physico-chemical sequences which is set going, utility or no utility, when- ever the mechanism of an individual is stimulated, he fully admits that the mechanism itself has come to be a character of the species by the oper- ation of natural selection. ‘‘ Naturally,” he says, ‘‘only those species whose inner character expressed itself in making these ‘suitable’ adjust- ments to the environment were able to survive.” Toward the close of his paper Professor Farmer seems to bring the con- siderations that have regard to the species into somewhat unnecessary conflict with those that have regard to the individual. Thus he says that ‘‘current literature still teems with teleological ‘explanations that really explain nothing, but rather bar the way of scientific enquiry.” A properly loaded, well-constructed modern gun goes off, for disadvan- tage no less than for advantage, when its trigger is pulled ; but the very existence of the gun depends upon a long succession of past stages, each of which was more advantageous than its predecessor. The recognition of this history does not bar the way of enquiry, but rather stimulates and suggests a searching and intelligent study of the latest mechanism with all its intricacy. + See the letter from Hooker to Darwin, March 17, 1862, in ‘‘ More -Letters,” vol. i, p. 197. § See the letter from Darwin to Lyell [June 14, 1860], ‘Life and Letters,” vol. ii, p. 319. ( 32) I will mention merely by way of illustration, that my attention has been called in recent years to the dwarfing effect of the prevalent south-western winds on the vegetation of the exposed chalk downs of the Isle of Wight. It has occurred to me as a mere suggestion, but one worth investigating, that the effect of wind upon a tall flower-head might be such as to render less easy and less frequent the visits of insects. If this were so, it would perhaps explain why certain species of entomophilous plants liable to grow in such situations have gained a special susceptibility to the stimulus provided by constant winds during some particular period of growth. The absence of this stimulus would also correspond to a condition in which the plants would gain in the conspicuous- ness brought about by increased height. The further growth of a class already proved to be large, would play havoe with a definition of species rigidly based upon discriminating structural characters alone. IV. Geographical Races or Sub-Species :—If we depend upon unaided diagnosis there is no means of discriminating between species and those sub-species of which the whole mass of in- dividuals are distinguished by recognisable characters. Here again the mere beginning of the difficulty is in sight; for as museums recognise more and more the necessity for long series of specimens with exact geographical data, so will the compara- tively simple conception of the single species be replaced again and again by the far more complex but much truer idea of sub-specific groups still fused by syngamy into a single species, but as it were trembling on the edge of disruption, ever ready, by the development of pronounced preferential mating or by the accumulated incidental effects of isolation prolonged beyond a certain point, to break up into distinct and separate species. V. Results of Artificial Selection ;—These obvious difli- culties encountered by a mechanical adherence to defini- tion by diagnosis naturally lead to the consideration of the further difficulties presented by domestic races of animals and plants. The wide structural differences be- tween the forms accumulated by human selection greatly impressed Darwin. Thus he wrote to Hooker, September 8, [1856]:—“ By the way, I have been astonished at the ( 33 ) differences in the skeletons of domestic rabbits. I showed some of the points to Waterhouse, and asked him whether he could pretend that they were not as great as between species, and he answered, ‘They are a great deal more.’ How very odd that no zoologist should ever have thought it worth while to look to the real structure of varieties. . . .’ * Then again, the differ- ences between many of our domestic breeds, and between them and the nearest wild species, are, as is well known, generic rather than specific. Why do we not consider such races to be of different species and genera? Because of the criterion sug- gested by Lankester ; because we have reason to believe in their descent from common parents within the historic period ; because, in spite of their wide differences, they are still syngamic, What is the practical bearing of these criticisms upon the definition of species by diagnosis and diagnosis alone? The systematist, confronted by his series of specimens in a museum cannot do otherwise than arrange them in groups which he will describe and nameas species. But much would be gained if he admitted at the outset that his conclusions are provisional, if he said with Dr. Karl Jordan, “The actual proof of specific distinctness the systematist as such cannot bring; ... we work, or we ought to work, with the mental reservation that the specific distinctness of our species nove deduced from morphological differences will be corroborated by biology.” + The advantage of thisattitudeis obvious. Work would goon as at present. Powers of acute observation and good judg- ment would still furnish descriptions of species to be hereafter confirmed or confirmed at the time by observation and experi- ment upon the living material. But the systematist would not only receive our gratitude for the performance of these important and necessary duties: he would also be seeking in every direction for the evidence of syngamy and of epigony. The museum would become a centre for the inspiration of researches of the highest interest to the investigator himself, of the greatest importance to the whole body of naturalists. * “More Letters,” vol. ii, p. 210, Letter 543. + “Novitates Zoologice,” vol. iii, Dec. 1896, pp. 450, 451. I here desire to express my indebtedness to the author of this learned and valuable paper. (oa) We now turn to the consideration of interspecific sterility, which many have supposed to be an_ infallible criterion. Huxley himself felt this so strongly that he was, in consequence, never able to give his full assent to natural selection. The grounds of his objection were the subject of prolonged correspondence with Darwin. In order to prove that natural selection has produced natural species separated rigidly, as he believed, by the barrier of sterility, Huxley maintained that we ought to be able to produce the same sterility between our artifi- cially selected breeds ; and until this had been done he could not thoroughly accept the theory of natural selection. This objection he expressed, or implied, in many speeches and writings up to within a few months of his death. One of the simplest statements is contained in a letter to the late Charles Kingsley. - Huxley wrote, April 30, 1863, “Their produce [viz. that of Horse and Ass] is usually a sterile hybrid. “So if Carrier and Tumbler, e.g., were physiological species equivalent to Horse and Ass, their progeny ought to be sterile or semi-sterile. So far as experience has gone, on the contrary, it is perfectly fertile—as fertile as the progeny of Carrier and Carrier or Tumbler and Tumbler. “From the first time that I wrote about Darwin’s book in the 7imes, and in the Westminster, until now, it has been obvious to me that this is the weak point of Darwin’s doctrine. He has shown that selective breeding is a vera causa for morphological species; he has not yet shown it a vera causa for physiological species. “ But I entertain little doubt that a carefully devised system of experimentation would produce physiological species by selection—only the feat has not been performed yet.”* It was against this same view, as expressed in Huxley’s ‘Lectures to Working Men” in 1863, that Darwin argued with convincing force in many letters. The main facts with which he confronted Huxley again and again were the artificially selected races of certain plants which are sterile inter se. The position is clearly expressed in the following amusing, vehement passages from two letters :— * «Life and Letters of Thomas Henry Huxley,” vol. i, p, 239. ( 35) “ Dec, 18, [1862.] “Do you mean to say that Girtner lied, after experiments by the hundred (and he a hostile witness), when he showed that this was the case with Verbascum and with maize (and here you have selected races): does Kolreuter lie when he speaks about the varieties of tobacco? My God, is not the case difficult enough, without its being, as I must think, falsely made more difficult? I believe it is my own fault— my d d candour: I ought to have made ten times more fuss about these most careful experiments.” * “*T Jan. | 10, (1863. ] “Tn plants the test of first cross seems as fair as test of sterility of hybrids, and this latter test applies, I will maintain to the death, to the crossing of varieties of Verbascwm, and varieties, selected varieties, of Zea. You will say, Go to the Devil and hold your tongue. No, I will not hold my tongue; for I must add that after going, for my present book [Variation under Domestication], all through domestic animals, I have come to the conclusion that there are almost certainly several cases of two or three or more species blended together and now perfectly fertile together. Hence I conclude that there must be something in domestication,— perhaps the less stable conditions, the very cause which induces so much variability,—which eliminates the natural sterility of species when crossed. If so, we can see how unlikely that sterility should arise between domestic races. Now I will hold my tongue.” + Darwin made attempts to ‘produce physiological species by selection,” and thus meet his friend’s criticism. He thought out and suggested a plan of experiment to W. B. Tegetmeier,{ and gave a brief account of the scheme to Huxley, December 28, [1862]:—“TI have given him [Tegetmeier] the result of my crosses of the birds which he proposes to try, and have told him how alone I think the experiment could be tried with the faintest hope of suecess— namely, to get, if possible, a case of two birds which when * “More Letters,” vol. i, p. 230, Letter 156. + Ibid. vol. i, pp. 231, 232, Letter 157. $ Ibid. vol. i, pp. 223, 224, Letter 153, [1862, Dec. | 27. ( 36 ) paired were unproductive, yet neither impotent. For instance, [ had this morning a letter with a case of a Hereford heifer, which seemed to be, after repeated trials, sterile with one particular and far from impotent bull, but not with another bull. But it is too long a story—it is to attempt to make two strains, both fertile, and yet sterile when one of one strain is crossed with one of the other strain. But the difficulty . . . would be beyond calculation.” * The experiment was evidently unsuccessful,—perhaps was never seriously undertaken,—and a few years later Darwin added the following postscript to a letter to Huxley, January 7 [1867]. “P.S.—Nature never made species mutually sterile by selection, nor will men.” t This was probably only an offhand expression of opinion, not intended to be taken seriously. An altogether hopeless attitude would not be reasonable until the suggested scheme had been applied many times, and in several parts of the animal and vegetable kingdoms. But the positive results demanded by Huxley, even if obtained, would by no means justify his far-reaching conclusions, If the barrier of sterility were thus artificially produced, we should be very far from the proof that its exist- ence in nature is due to the same kind of cause, viz. selection. If Darwin was right in his controversy with Wallace, if “Nature never made species mutually sterile by selection,” the suggested experiment would merely do by artificial selection what is not done by natural selection. It is by no means difficult to understand the mutual sterility which is usual between natural species as an incidental result of their separation by asyngamy for a long period of time. In the process of fertilisation a portion of a single cell nucleus from one individual fuses with a portion from another in- dividual, the two combining to form the complete nucleus of the first cell of the offspring, from which all the countless cells of the future individual will arise by division. Each part-nucleus contains the whole of the hereditary qualities * “* More Letters,” vol. i, pp. 225, 226, Letter 154. + Ibid. vol. i, p. 277, Letter 197. (eae )) received from and through its respective parent, and must therefore be of inconceivable complexity.. We can only speak in generalities about processes of which so little is known, but we cannot be wrong in assuming that sterility is some- times due to the fact that the complex architecture of one part-nucleus fails in some way to suit the equally complex structure of the other. The individuals of an inter-breed- ing community form a biological whole, in which selection inevitably keeps up a high standard of mutual compati- bility between the sexual nuclei. Individuals whose sexual nuclei possess a structure which leads to sterile combinations with those of other individuals are excluded from contributing to the generations of the future. As soon, however, as a group of individuals ceases, from any reason, to breed with the rest of the species, there is no reason why the compati- bility of the sexual nuclei of the two sets should be retained. Within each set, selection would work as before and keep up a high standard of compatibility ; between the sets, com- patibility would only persist as a heritage of past selection, gradually diminishing as slight changes of structure in either or both of the sets rendered them less and less fitted to produce fertile combinations.* It is probable that of all the nice adjustments required in the living organism, the mutual adjustment of these incon- ceivably complex part-nuclei is the most delicate and precise. Now, delicately adjusted organs, such as those of sight, rapidly become incapable of performing their functions when in any species they have been withdrawn from the operation of natural selection ; similarly it is suggested, that the adjustment of sexual nuclei to each other would sooner or later give way * IT must guard against the inference that the only explanation of sterility is here set forth. It is indeed maintained that incompatibility of the sexual part-nuclei is the inevitable outcome of enduring asyngamy, and is the almost certain cause of the sterility of hybrids. And it may be suggested that sterility is a result of the combination of two incom- patible germ-plasms in the sexual cells of the hybrid. When the incompatibility is not strongly marked we can understand how such sexual cells may be capable of fertile fusion with the cells of either parent, but not with those of another hybrid. But short of these ultimate effects it must not be forgotten that there are many obscure factors of asyngamy—causes of various kinds which interfere with the fusion under normal conditions or entirely prevent the meeting of the sexual cells. ( S85 )) when no longer sustained by selection, If, then, mutual fertility be the result of unceasing selection, and mutual sterility the inevitable, even if long-postponed, consequence of its cessation, it is obvious that Huxley’s difficulty is solved, while his suggested experimental creation of sterility by selection would not reproduce any natural operation: it would afford a picture of a natural result but would be produced in an unnatural way. This criticism of Huxley’s contention was advanced by the present writer three years ago,* the final conclusion being stated in the paragraph printed below :— ““Tf, then, we cannot as yet reproduce by artificial selection all the characteristics of natural species-formation, but can only imitate natural race-formation, we can nevertheless appreciate the reasons for this want of success, and are no more compelled to relinquish our full confidence in natural selection than we are compelled to adopt a guarded attitude towards evolution because our historical records are not long enough to register the change of one species into another.” T Tt was therefore with intense interest and pleasure that I read the following sentences in a letter written by Darwin to Huxley, Dec. 28, {1862]—sentences which show that criticism practically identical had been made by the illustrious naturalist nearly forty years earlier. ‘‘We differ so much that it is no use arguing. To get the degree of sterility you expect in recently formed varieties seems to me simply hopeless. It seems to me almost like those naturalists who declare they will never believe that one species turns into another till they see every stage in progress.” { After reading, in the first volume of ‘‘ More Letters,” the often-repeated refutation of Huxley’s objection so clearly and strongly expressed in letters received by the objector himself, it is surprising that no effect was produced, and that reference should have been nearly always made to this supposed flaw in the theory of natural selection, whenever the great compara- * «The Quarterly Review,” No. 385, January 1901, pp. 368-371. 1p (hos 1 BHA + ‘More Letters,” vol. i, p. 225, Letter 154, Cpe 2) tive anatomist had occasion to speak or write on the broader aspects of biological inquiry.* Darwin also considered that there was something in the very conditions of domestication which tended to promote fertility between races and even between distinct species. Thus he followed Pallas in believing that the domestic dog has been derived from more than one wild species, although he did not trace existing differences to this cause but to artificial selection.t However, as regards the origin of the dog, “the evidence is, and must be, very doubtful,” as he wrote to Lyell, August 11, [1860]. The fact which Darwin “ considered the most remarkable as yet recorded with respect to the fertility of hybrids,” was the fertility of the offspring of the Common and Chinese Goose, originally described by Eyton, and confirmed by Goodacre and by Darwin himself. ‘The two species of goose now shown to be fertile inter se are so distinct that they have been placed by some authorities in distinct genera or sub- 4 genera.” { Another interesting and exceedingly difficult experiment in hybridisation has been carried through by the Rev. P. St. M. Podmore, F.Z.8., who in Sept. 1899, after numerous failures, succeeded in rearing a healthy male hybrid between the Ring Dove (Columba palumbus) and the domestic pigeon. On May 27, 1903, this male was mated with a Blue Homer hen, which produced healthy offspring. § * For several instances see Poulton’s ‘‘ Charles Darwin and the Theory of Natural Selection,” Lond. 1896, pp. 124-141. + “Though I believe that our domestic dogs have descended from several wild forms, and though I must think that the sterility, which they would probably have evinced, if crossed before being domesticated, has been eliminated, yet I go but a very little way with Pallas & Co. in their belief in the importance of the crossing and blending of the aboriginal stocks. * * * * * * * * ** Although the hound, greyhound, and bull-dog may possibly have descended from three distinct stocks, I am convinced that their present great amount of difference is mainly due to the same causes [artificial selection] which have made the breeds of pigeons so different from each other, though these breeds of pigeons have all descended from one wild stock ; so that the Pallasian doctrine I look at as but of quite secondary importance.” ‘‘More Letters,” vol. i, pp. 127, 128, Letter 80, to Lyell, Oct. 31, [1859]. t ‘‘ Life and Letters,” vol. iii, p. 240. § ‘‘The Zoologist,” Noy, 19038, p. 401. eey A comparison between the difficulty of producing such a cross and that of obtaining hybrids between the Ring Dove and the Rock Pigeon, the ancestor of the domestic breeds, would probably throw much light on the Pallasian hypothesis. If the view here proposed be sound—that syngamy lies behind, and is at least provisionally implied in the transition which means so much to the systematist, and is his only real evidence when the structural test breaks down, the conclusion is suggested that the real interspecific barrier is not sterility but asyngamy. Nevertheless, as argued on pages 36-8, asyngamy will infallibly lead to sterility, although the result may be long delayed. This latter view, which was that of Darwin, is the exact opposite of the ‘“ physiological selec- tion” of Romanes, in which sterility is supposed to arise spontaneously, asyngamy being not the cause, but the consequence. Asyngamy may be brought about in various ways, of which the most obvious is geographical separation. But asyngamy is by no means the necessary result of geographical discon- tinuity or asympatry. Thus Darwin considered that there is regular inter-breeding between Madeiran and continental birds of the same species. He wrote to Hooker, August 8 [1860]. “I do not think it a mystery that birds have not been modified in Madeira. Pray look at p. 422 of Origin [ed. iii]. You would not think it a mystery if you had seen the long lists which I have (somewhere) of the birds annually blown, even in flocks, to Madeira. The crossed stock would be the more vigorous.” * An even more striking case is that of Pyrameis cardui, which ranges over nearly the whole world. The singular absence of local geographical races in this abundant butterfly is almost certainly due to the astonishing powers of dispersal which enable intermittent syngamy to prevail over the whole vast area of its distribution. An interesting and curious cause of persistent asyngamy is the ‘‘ Mechanical Selection” so thoroughly explained and abundantly illustrated by Karl Jordan.7 The complex genital armature of Lepidoptera is during syngamy kept constant by * “¢ More Letters,” vol. i, pp. 487, 488, Letter 370. + lc. p. 518-522. Cees) unceasing selection. Comparatively brief isolation of a group of individuals may lead to a departure from the specific type of apparatus prevalent in other areas, and may thus mechanic- ally prevent syngamy if from any cause members of the group became again sympatric with those of the parent species. A very different but exceedingly interesting origin of asyngamy is suggested by observations which support the conclusion that varietal forms may show a tendency towards preferential inter-breeding. H. W. Bates believed that he had strong evidence for the existence of this tendency in the races of certain tropical American butterflies. He stated this in his epoch-making paper on the butterflies of the Amazon valley,* and it is interesting to observe in the published letters how Darwin instantly fixed upon the point and tried to elicit the data upon which the conclusion was formed. Thus he wrote to Bates, Nov. 20 [1862]:—“ No doubt with most people this [viz. the interpretation of Mimicry] will be the cream of the paper; but I am not sure that all your facts and reasonings on variation, and on the segregation of complete and semi- complete species, is not really more, or at least as valuable, a part. I never conceived the process nearly so clearly before ; one feels present at the creation of new forms. I wish, however, you had enlarged a little more on the pairing of similar varieties ; a rather more numerous body of facts seems here wanted.” fT Then a few days later we find Darwin still thinking of the subject, and writing to Hooker [1862, Nov.] 24:—‘I have now finished his [Bates’] paper . . .; it seems to me admir- able. To my mind the act of segregation of varieties into species was never so plainly brought forward, and there are heaps of capital miscellaneous observations.” { He also again wrote to Bates, probably on the following day, Nov. 25 [1862 1%], asking for the solid facts which are so greatly wanted :— “Could you find me some place, even a footnote (though * Trans. Linn. Soe., vol. xxiii (1862), p. 495. + ‘‘ Life and Letters,” vol. ii, p. 392. £ ‘*More Letters,” vol. i, p. 214, Letter 147. ( 42.) these are in nine cases out of ten objectionable), where you could state, as fully as your materials permit, all the facts about similar varieties pairing—at a guess how many you caught, and how many now in your collection? TI look at this fact as very important ; if not in your book, put it somewhere else, or let me have cases.” * Remembering that Mr. Roland Trimen, F.R.S., had expressed the same opinion as the result of his wide and long experience of South African butterflies, I asked him if he would kindly furnish me with a statement. His reply, dated Dec. 28, 1903, is as follows :— ** Dec. 28, 1903. “T have noticed the tendency of the sexes of a variety to pair together rather than with other varieties in the numerous cases of captured pairs sent to me by correspondents in South Africa, and sometimes in cases of the same kind which occurred to myself when collecting. The species which particularly attracted my notice in this way during my visit to Natal was Hypanis acheloia (= Gitzius, Herbst, part), which is curiously variable on the underside, from pale creamy to deep chocolate. I did not know of its seasonal variation at the time, but I was in Natal just at the change of season from wet to dry, when the intermediate gradations were about, and I was struck with the close resemblance of the sexes in pairs that I caught. I am sorry to have nothing more definite to give on this head ; it is a point much requiring exact and prolonged observation.” Mr. Trimen furthermore entertains no doubt that much, if not all, of the material upon which he based the conclusion that the individuals of the same race tend to interbreed, exists, distinctively labelled, in the South African Museum, at Cape Town. It is greatly to be hoped that collectors will in future carefully label all specimens captured in cottu, and that the fact will be recorded on the labels in museums and in private collections. It is tantalising to reflect upon the number of interesting and important questions which could be now decided if this practice had prevailed during the past fifty years. The question of the possible origin of species * “More Letters,” vol. i, p. 215, Letter 148, ey) from races by preferential syngamy is of such high import- ance that we may confidently hope that the attention here directed to the question, and especially the quotation of Darwin’s letters to Bates, may lead to that “exact and prolonged observation,” accompanied by careful records, with- out which a safe decision cannot be reached. In the meantime the decided impressions of two such naturalists as H. W. Bates in South America and Roland Trimen in South Africa render it in every way probable that the conclusion will be established on a firm foundation.* It is also possible that asyngamy may be brought about by the breaking of what we may call “a syngamic chain.” In the case of large and widely-distributed interbreeding communities, it is an open question whether syngamy would freely take place between the most distant of the outlying sections if directly brought into contact, and whether, even if syngamy prevailed, there would be any diminution in fertility. Limnas chrysippus, perhaps the commonest butterfly in the world, forms a probably continuous syngamic chain stretching from the Cape of Good Hope at least as far as Southern China. It is even reported from Japan. The far Eastern forms are readily distinguishable by the greater size of a single white spot, giving quite a different appearance to the fore-wing. If pup or eggs were transferred from Hong-Kong or Macao to South Africa, would the perfect butterflies freely interbreed * Dr. T. A. Chapman sends me the following interesting and suggestive note :— “I met lately with a curious instance that deserves following up, of some bearing on the question of selective mating of varieties, “*T saw some broods of P. phlwas lately that differed from each other, but each brood was remarkably uniform. There were three broods, all bred in the same conditions, in a greenhouse (by Mr. Carpenter of Leatherhead). It seems difficult to explain this, unless both parents of each brood were very nearly identical. “Mr. Frohawk, who has bred the species largely, tells me he has noticed similar facts. “When I bred Acronycta tridens and psi largely, some fifteen or more years ago, I noticed that each brood had its own pairs, and suggested that tridens was now trying to break up into separate species just as some ancestor split into psi, tridens and cuspis. *‘ Another fact I observed in Acronycta rather bears on the other side of the question. Of 4. strigosa I reared a large brood, which paired readily and frequently together, but no eggs were laid. I then got some captured males, which paired with equal readiness with the bred females, and as a result obtained plenty of fertile eggs.” (C44) with the indigenous forms of chrysippus ? We do not know; but it is an experiment well worth trying, and one which would yield results valuable in many ways. If inter-breeding did not take place, or if the unions were sterile, then we should have the interesting case of a single species which would instantly become two if through any circumstance a central link dropped out of the chain. Even if chrysippus yielded negative evidence in this respect, it is highly probable that other widely-distributed species would, under these cir- cumstances, fall into two or more groups, each held together by inter-breeding, and divided from others by asyngamy. Sterility, if present in any degree, would have been brought about quite independently of selection ; for in such cases each link of the chain would be freely syngamie with the links on either side, and asyngamy or sterility would only be revealed by artificially bringing together the widely-separated ends of the chain. I cannot but think, therefore, that such experiments made upon many carefully-selected species would probably bring important additional evidence to bear upon the controversy as to whether sterility between species is, as Wallace believes, a selected quality, or, as Darwin held, an incidental one. The deep interest of this question is realised when we thus re- member that the two discoverers of natural selection held widely different opinions about it. We cannot read the letters on both sides, printed in the first volume of “ More Letters,” without realising how deeply this divergence—one of the principal differences between them—was felt by the two great naturalists. This is one of the many reasons for which I plead with Mr. Roland Trimen for the establishment of tropical bio- logical stations where work of the kind could be carried on. Such establishments should be associated with and be under the control of museums at home, where the experiments could be directed and the results studied and made available for all time for the researches of the naturalist. Just as Harvard has her main Observatory at the University, but also maintains an outlying institution in the Peruvian Andes, where certain kinds of research, unsuited to New England, ( 45 ) can be carried on under the most favourable conditions, so our chief museums should be provided with the means of establishing temporary stations in the most favourable parts of the tropics. When I say temporary, I do not refer to the means, but to the position of the station, which should be freely movable in response to the call of important problems as they present themselves for solution in other localities. Another urgent reason for the establishment of biological stations is forced upon us by the inadequacy of diagnosis for the separation of very variable species, such as many of the African Acraine. I cordially agree with the view often expressed to me by my friend Mr. F, A. Heron, that we shall never reach a secure foundation until synepigonic series have been obtained on a large scale. To achieve this end a temporary station would be required. In this way our museums could receive, and should keep for permanent study, the whole of the offspring reared from the eggs of a single parent. If several species were thus represented by one or more large synepigonic series, we should know what to expect and what to allow for; and diagnosis in general would gain the most helpful guidance. Asyngamy, as regards particular lines of union, has also been incidentally brought about by certain adaptations for cross-fertilisation in plants, and such asyngamy has in some cases persisted long enough to have led to sterility in greater or less degree. Of all Darwin’s work, that upon the fertilisation of heterostyled plants threw most light, he considered, upon sterility between species. As Francis Darwin has stated, “ He found that a wonderfully close parallelism exists between hybridisation and certain forms of fertilisation among heterostyled plants. So that it is hardly an ex- aggeration to say that the ‘illegitimately ’ reared seedlings are hybrids, although both their parents belong to identically the same species. In a letter to Professor Huxley, given in the second volume [of ‘Life and Letters’], p. 384, my father writes as if his researches on heterostyled plants tended to make him believe that sterility is a selected or acquired quality. But in his later publications, e.g. in the sixth edition of the ‘Origin,’ he adheres to the belief that sterility Ce) is an incidental rather than a selected quality. The result of his work on heterostyled plants is of importance as showing that sterility is no test of specific distinctness, and that it depends on differentiation of the sexual elements which is independent of any racial difference.” * The different forms of a heterostyled plant are adapted for cross-fertilisation by insects, and each individual of each form is by the same means excluded more or less completely from fertilisation by another of the same form. In the former case the sexual cells and the accessory apparatus have been kept by selection during long generations of syngamy in a high state of mutual compatibility ; in the latter asyngamy, partial or complete, has produced a large measure of the sterility which is its inevitable even if long-delayed result. This argument has, I admit, carried me much further than I originally intended, and it will be a pleasure to me if the following criticism can be overthrown. If the special adaptation of heterostyled plants for particu- lar lines of syngamy has incidentally resulted in lessened fertility, when the unions discouraged by these adaptations are artificially secured, and in this case without appeal to the physiologically injurious effects of self-fertilisation, why should we not similarly explain these effects whenever manifest in the self-bred + offspring of any plant especially adapted for cross-fertilisation 1 Darwin tells us in the Autobiography that as soon as his “attention was thoroughly aroused to the remarkable fact that seedlings of self-fertilised parentage are inferior, even in the first generation, in height and vigour to seedlings of cross-fertilised parentage,” {| he entered upon a series of experiments which lasted eleven years, appearing in 1876 as “‘ Effects of Cross and Self-Fertilisation in the Vegetable Kingdom.” Of this work he wrote in 1881, “the results there arrived at explain, as I believe, the endless and wonder- ful contrivances for the transportal of pollen from one plant to another of the same species.”§ It is here suggested that * «Life and Letters,” vol. iii, p. 296. + See Francis Darwin on ‘‘The Knight Darwin Law,” Nature, October 27, 1898, p. 630. t ‘*Life and Letters,” vol. i, p. 96. § Ibid., vol. i, p. 97. ( 47 ) these injurious results have been not_ the cause but the con sequence of specialisation for cross-fertilisation. In such plants fertil sation is mainly brought about along the line for which special adaptation is made: self-fertilisation is relatively infrequent, often very rare, sometimes perhaps absent altogether. May not the less successful results have followed from a condition in which self-fertilisation is but little tried by the fires of selection? * It would be of much interest to compare a long series of experiments on the cross- fertilisation of plants which are habitually self-fertilised and on the self-fertilisation of plants in which the adaptations for cross-fertilisation are made use of in widely different degrees. This criticism, should it be sustained, would of course throw much light upon the case of the Bee Orchis and the numbers of tropical Orchidacez, etc., which are now known to be regularly self-fertilising without apparent physiological injury. It might also have a bearing upon an intrusive set of facts which must often have weighed upon the minds of naturalists as they reflected upon the commonly received hypothesis that assumes the dangers of continued breeding between near of kin. A. R. Wallace speaks of these facts in “ Darwinism,” + and I have drawn attention to them in dis- cussing the meaning of insect migration, although, as will be seen in the following passage, without any serious doubt as to the physiological significance of cross-fertilisation. { “We may well inquire why it should be necessary for such emigration, with a possible successful issue in colonisation, to require the services of countless individuals when the importa- tion of half-a-dozen rabbits or a few specimens of Pieris rapx will, for the naturalist, change the face of a continent. The results of these unintentional, or intentional but ill-considered, experiments do indeed shake the belief in the paramount necessity for crosses and the dangers of in-and-in breeding ; but the end is not yet, and the teeming colonies which have arisen from such small beginnings may in time vanish from the operation of deep-seated causes. The varied adaptations for cross-fertilisation and the prevention of in-and-in breeding * See also A. R. Wallace in ‘‘ Darwinism,” London, 1889, pp. 321-326. + p. 326. ~ Trans. Ent. Soc. Lond., 1902, pp. 460-465. ( 48 ) are so evident in nature, that we are compelled to believe that they meet and counteract serious dangers which sooner or later would menace the very existence of the species. And among other adaptations it is significant that the instinct under discussion should lead to the streaming of large popula- tions, and not of small batches of individuals, from an area of high-pressure.” * It is impossible to consider the advantages which may have favoured cross-fertilisation, if hereafter the generally accepted physiological necessity turn out to be a delusion. Brief reference may, however, be made to the special advant- ages of community which are possible through syngamy alone. By inter-breeding the favourable variations arising in one direction are combined with others arising in different direc- tions ; by the kaleidoscopic changes produced by inter-breeding more varied results are presented for selection, and the bene- ficial qualities arising in one part of the mass may quickly become the heritage of the whole ; by inter-breeding excessive spontaneous variation is checked, and the whole community of the species advances surely and with stability into adjust- ment with the progressive changes of the environment. Weallremember Darwin’s beautifully elaborated metaphor T by which the past history of evolution is shown forth in the form and branching of a great tree. Darwin represented species by the “green and budding twigs,” and we may suppose that the leaves stand for individuals, and that syn- gamy is represented by the contact of leaf with leaf when the branches sway in the wind. And just as contact may run through large and small, irregular and compact masses of leaves, so syngamy binds together groups of varying size and distribution. So too a mass of foliage breached by a sudden storm pictures for us the splitting of a syngamic chain into two species by the disappearance ef an intermediate link. It has been a pleasure to me that the central idea which I have endeavoured to bring before you should be represented, I trust without violence to the imagery, by means of “the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever-branching and beautiful ramifications.” { * le. p. 464. + ‘Origin of Species,” 1859, p. 129. 1 2.1, Derlads Lon AN ADDRESS ENTITLED THE BEARING OF THE STUDY OF INSECTS UPON THE QUESTION “ARE ACQUIRED CHARACTERS HEREDITARY 2” READ BEFORE THE ENTOMOLOGICAL SOCIETY OF LONDON AT THE ANNUAL MEETING ON THE 18TH JANUARY, 1905. BY Pror. EDWARD B. POULTON, D.Sc., M.A., Hon. LL.D. PRINCETON, 1A Sbp HOPE PROFESSOR OF ZOOLOGY IN THE UNIVERSITY OF OXFORD, FELLOW OF JESUS COLLEGE, OXFORD, President of the Society. i. _ > alee eee 9%, A fe a er _ ; ee wee ie or ' 7 aL? thd. A Peas ee id: FP e a el ees 8 ay a yearn ie> * ote coe wee i ~ ee ’ , i 10 , ih % rely 7 ai) _ zs Ty ee i fh m ian 7 - : t ee 1)! ' a ; ; ee 7 a 7 a BS Baer) eAjaert oe — Sh Rat sae a a , ; \ 7 e , | - i . - oS. Meme Try UP ee ee | APOR GE a : a Wy ; ; ‘ ne —_—_—- ; I a ' ,) jaa 7 Te ; Wy : z 7, h 14 i] ® 2 7 it ue + i _ os i { = » ia _ a = i. a an r ; 2° 7 7 i s a =" La te " 7 PO Py =! a ; 7 os Ps . ‘ve ? a ww o q » ’ i , . ‘pre ; j tf a ; ; F m. A 7 ‘ A » a = i) ert ide ~ aha T or ‘ i & i > o@ ave u 5 oy): the dias bees —. | : a.) ‘ a s 7 7 : 7 -—é ! i rT 7 anfiii i ae bee he - a } ; s F 7 | 7 , ie) ; pee ‘? ve - q ; ; a, -. re iN THE PRESIDENTS ADDRESS. GENTLEMEN, Ir is a great pleasure to be able to congratulate the Society on another year of prosperity. I need add no words on this subject to the Report of the Council. The thoughts of prosperity and stability are inevitably associated with the memory of one who worked long and hard to secure these advantages for us, of one whose death in the midst of his official work will always invest the past year with peculiar pathos. All that has been gained by the devotion of our late Treasurer will, we know full well, be preserved for us by the care and skill of his successor, who most kindly con- sented to come forward and help us, almost without notice. I am sure that you will wish to express special gratitude to Mr. Albert H. Jones for his services to the Society under circumstances of great difficulty and sorrow. The loss of so important an officer as the Senior Secretary is a serious event in the history of any Society, and in the retire- ment of Mr. Herbert Goss we are losing one who has served as an otticer for the record-breaking period of fifteen years. He first entered the Council in January 1885, and was almost at once induced to accept the Secretaryship, holding the position from 1885 to 1897. The Society, however, could not assent to his permanent withdrawal, and in January 1901 he was again elected to the office which he held until his retirement on the present occasion. We shall greatly miss his genial presence from the official chair, as well as the advancement of the interests of the Society which his position enabled him to promote so successfully. Our warmest wishes go with him: we know that the feelings which prompted him to do so much for our community in office will still remain the same out of office, and that the Society has no more loyal member or truer ( 2) friend. We are fortunate in securing as his successor one who has already acted as Secretary, and knows full well the difficulties and responsibilities as well as the keen interest and the honour that belong to the position. To his many other qualifications Commander Walker adds this supreme qualifi- cation. The Society has never had an officer with a wider experience of Entomology, or one who, from his capacious and varied store—material and mental—has more freely extended help and sympathy to his brother Fellows. Amid these changes we remember with especial gratification that the tried and trusted services of our Librarian, Mr. G. C. Champion, and of Mr. H. Rowland-Brown, who now becomes Senior Secretary, are still to be employed for the benefit of the Society. Ropert MchLacuian, F.R.S.—No more pathetic event has happened, in our history of well nigh three-quarters of a century, than the death of a chief officer, in the midst of the work which ke loved,—work which, in spite of the weakness and anxiety induced by ill-health, always commanded his devotion and energy. So full of zeal was our late Treasurer for the welfare of the Society, that there is reason to fear that the inability to perform the important duties of his responsible post was a bitter disappointment added to the inevitable troubles of illness. It is some satisfaction to know that the Council took every possible step to allay that anxiety, and to feel that their action was attended by some measure of success. In the “Chapter of an Autobiography,” which forms the concluding part of McLachlan’s second presidential address to this Society * we gain very clear knowledge of the early age at which he showed himself pre-eminently fitted to be a student of Nature. This is probably always true of those who are to achieve high distinction in this great school of learning. We may give opportunity generously, and be the richer for the free growth of genius under the most favourable con- ditions: we may refuse opportunity and receive as our due deserts a power which makes for good cramped and stunted. But under any circumstances the power itself is from within. * Proc. Ent. Soc. Lond. 1886, p. 1xxxi. (e.2 -) A great naturalist no less than a poet “is born, not made.” Science is fortunate in the circumstances which surrounded the youth of Robert McLachlan :—childhood up to the age of fifteen spent on the borders of Hainault Forest, with all the varied interests botanical and zoological which such surround- ings would awake in those with eyes to see them,—removal to London with its stores of literature within easy reach and kind friends to aid the young student in the search—the experience, so inspiring to the naturalist, of a long voyage, with two months’ hard work plant-collecting in Australia—an introduction on the return home to the great Robert Brown who gave first kind help, then sound advice. Then after this broad foundation in natural history as a whole, the stimulus towards special work received at the psychological moment from the writings of Hagen. To this inspiration, when he was about twenty-three, we can trace the growing interest which culminated in the great work of McLachlan’s life, the ‘‘ Mono- graphic Revision and Synopsis of the TZvrichoptera of the European Fauna” (1874-1880), appearing between the ages of thirty-seven and forty-three. ‘To his early training is due that rare breadth of knowledge and interest which made him so ready and learned a contributor to the discussions at our meetings—so valuable a helper to those who came to him for advice. Robert McLachlan was a Fellow of the Society for nearly half a century, having been elected in 1858. Heacted as Secretary from 1868 to 1872, as Treasurer from 1873 to 1875 and again from 1891 to the time of his death. He was President in 1885 and 1886. I have already spoken of his remarkable devotion to the Society. A certain apparent cynicism formed a veil which to a large extent concealed the real man from the sight of all but intimate friends. But there existed beneath a zeal and a strenuousness in disinterested service which is utterly inconsistent with cynicism. At times when the Society has been divided by conflicting opinion it has been my privilege to know that his own feelings were far less concerned with the subject of dispute or with the success of either party, than they were with the Society itself, in grave anxiety lest it should be injured by the struggle. In thus speaking, as is OO wee) only due, of his patriotic devotion to the Entomological Society of London, it is right to place beside it the “ Entomologist’s Monthly Magazine” which he served with equal zeal. He acted as an Editor from the very commencement in 1864, and upon the death of H. T. Stainton in 1902 became proprietor. It is not necessary on this occasion to do more than allude to the long list of valuable memoirs, chiefly dealing with the Neuroptera, but by no means confined to this Order, which came from his pen. They were communicated to the scientific literature of many lands, and their author received from numerous scientific Societies on the Continent the highest honour which is in their hand to bestow. His election to the Fellowship of the Royal Society in 1877 took place in the midst of the years during which his Monographie Revision of the Trichoptera was being given to the world, and is an interesting indication of the instant recognition won by that great work. I have not thought it necessary or even advisable on this occasion to repeat the whole of the interesting details of McLachlan’s life and work which are to be found elsewhere.* Here, and in the special circumstances of his death while still holding the reins of office, I have preferred to speak chiefly of his relations to this Society, and of the circumstances which contributed to make him so valuable a member of our community. I trust I have been able to bring before you some of the reasons for the high honour that will ever be due to the memory of the warm friend the Society has lost. CHARLES GOLDING Barrerr joined the Society in 1884. By his death on December 11 we lose one of our most valued Fellows and an indefatigable worker. He was born at Colyton, Devonshire, on May 5, 1836, and entered the Civil Service in June 1856. He passed through the usual stages of promotion up to 1875, when he was appointed a Supervisor of Excise. In 1884 he was promoted to an Inspectorship, and was made a Collector of Inland Revenue at Lynn in July 1886. He was further promoted to a first-class Inspectorship * “¥Entomologist’s Monthly Magazine,” July 1904, pp. 145-148. The Royal Society. Obituary. ‘‘ Entomological News,” September 1904, pp. 226, 227. Gr} in October 1889, and subsequently, in August 1895, he became Collector of London South, where he remained until pensioned in April 1899. Throughout this long and varied official life his genial nature and kindliness of spirit endeared him to all his colleagues.* The successive stages of such a career implied residence in different parts of the kingdom, bringing opportunities of studying the fauna and flora of varied districts, opportunities most welcome to this ardent naturalist, In writing the following brief statement of Barrett’s distinguished entomological career, I desire to acknowledge the assistance received from Commander Walker’s sympa- thetic account in the “ Entomologist’s Monthly Magazine.” The absorbing interest of Parrett’s life became manifest in his boyhood. The first published observations which can be traced to his pen appeared in 1856, when he was twenty (‘ Entomologist’s Weekly Intelligencer,” vol. i, p. 165), and from this time until the end of his life he was a constant contributor to Entomological literature. His name appears in the Index of the “ Entomologist’s Monthly Magazine,” as the author of no less than 330 separate communications. When we remember that this periodical only came into existence in 1864, we gain some idea of his energy and industry. Our knowledge of the Lepidoptera in varied and widely separated parts of the British Islands has been greatly extended, as the late naturalist moved from one district to another :—to Dublin in 1859, to Haslemere in 1862, to Norwich in 1868, to Pembroke in 1875, to King’s Lynn in 1886. Barrett’s great work on ‘The Lepidoptera of the British Islands” was begun in 1892, and all British naturalists will deeply regret that the guiding hand is no longer here to complete it. We shall miss his experience and control ex- actly where it will be wanted most—in the Micro-Lepidoptera. In fact many have regretted, as they saw the length to which re-description and re-illustration of things pretty well known * T owe the information concerning Mr, C. G. Barrett’s official career to the courtesy of the Editor of ‘‘ The Civilian.” A2 (8) were carried in the earlier volumes, that the author had not reversed the method of his building, and begun with the Micro-Lepidoptera. C. G. Barrett became a Fellow of our Society in 1884. He served on the Council in 1892-3, and again in 1900-01, and was a Vice-President in 1901. He was President of the South London Entomological Society in 1892, and was an important member of the editorial staff of the “ Entomologist’s Monthly Magazine” from 1880 until his death. We deplore the loss of one who was ever ready to help his brother naturalists, one who invariably acted up to the high standard of those words which accurately express the living principle of our Scciety :—that we “are all members one of another.” We have also to mourn the loss of two Fellows who have joined our community within recent years :—E. G. J. Sparke, B.A., elected in 1897, and W. F. Urwick, elected in 1900. Both were well-known collectors of insects, comrades of Fellows, still happily with us, on those delightful occasions when friendships are made and deepened by companionship in the pursuit of a common interest. Just as the year came to a close, on December 29, the Entomological world suffered irreparable loss in the death, in his seventy-third year, of one of the most distinguished of the twelve great names which stand at the head of our “ List of Fellows,” Professor Frrepricu Moritz Braver, of Vienna. Brauer’s first entomological publication, a revision of the genus Chrysopa, appeared in 1850, and in the course of the next few years he published numerous papers on the biology of the Neuroptera, rapidly rising into the front rank of the European students of that order. In 1858 Brauer was attracted by the curious life-history of the Dipterous family, Oestridx, upon which he carried out the most minute and painstaking investigations, culminating in the publication, in 1863, of his classical ‘‘ Monographie der Oestriden.” Even with his great ability the production of such a work would have been impossible had he not been almost entirely free from other pre-occupations. This fortunate result was rendered possible by his position as an Assistant (er >) in the University Entomological Museum. In 1873 he was appointed Custodian of these Entomological Collections, and in 1874, Professor of Zoology in the University. At the time of his death he was a Director of the Naturhistorisches Hofmuseum. Brauer’s researches into the biology of the Oestridx led him to found the two great divisions of Diptera—‘‘ Cyclorrhapha ” and “Orthorrhapha,’ based upon the form of the pupa. Further researches into the metamorphoses not only of Oestridx, but throughout the Order, led to the publication, in 1883, of a new “System of Diptera,” which, with certain modifications, is still considered to be the best as yet brought forward. Latterly Brauer turned his attention to the parasitic Muscidx (Tachinidx, ete.), and, in collaboration with Julius von Bergenstamm, published a work which marks a consider- able advance in the classification of these groups. The fundamental importance of Brauer’s discoveries in two such sharply contrasted sections as the archaic Neuroptera and the comparatively modern, highly-specialized Diptera, fitted him in a very special way to study the broad and difficult question of the classification of the Insecta. His conclusions (System- atisch Zool. Studien, SB. Akad. Wien. xci. Abth. i. 1885, p. 374), “based upon recent advances in anatomy and em- bryology,” were adopted in Dr. W. Hatchett Jackson’s learned edition of Rolleston’s ‘Forms of Animal Life” (Oxford, 1888). The most prominent feature of Brauer’s classification is the splitting up of the Neuroptera into no less than 7 Orders out of the entire number of 17 adopted by him. An interesting discussion and criticism of the system appeared in Dr. David Sharp’s contribution to the Cambridge Natural History (Insects, Pt. i., London, 1895, p. 175). I have to thank Mr. J. E. Collin for much kind help in drawing up this brief account of the distinguished scientific man whose loss will be so deeply felt by biological Science throughout the world. The Fellows of this Society will feel, in common with the members of other associations occupying this building, deep regret at the sad death of the late Resident Librarian, Mr, ep William R. Hall. Long years of loyal and efficient service have left an enduring memory. Before I proceed to the subject of my address there is one important point upon which I feel bound to warn not only this Society, but other Scientific Societies as well. I refer to the enduring qualities of the paper on which scientific publications are often printed, and still more emphatically the ‘‘ paper” on which they are often illustrated. I allude especially to the so- called ‘‘art papers,” assuredly named on the principle “ ut lucus a non lucendo.” ‘The opaque, white, polished surface, which yields the most successful “half-tone” and “three-colour”’ printings, is at present only possible by means of a veneer of china-clay. Dust it is, and we are assured by experts that not many years will pass by before it succumbs to the fate which the highest authority tells us is in store for dust. For the purposes of advertisement, this is no disadvantage: the cynic may even maintain that the writings of the present day are, to the great benefit of the human race, recorded upon a fitting medium. But cynicism has no part in science, and every Fellow of this Society will agree that an age producing scientific records which cannot be made to endure, is an age to be rightly scorned by the generations of the future,—scorned as one that sunk to the lowest level of production, that, intellectually, owing its very existence to the noble standard reached by days yet earlier, took the benefits, and deliberately or carelessly neglected in like manner to assist 1ts successors. We have only to reflect upon the paramount importance of tradition in order to realize the weight of our responsibilities. Lloyd Morgan, discussing the trend of human development, speaks of a “ transference of evolution from the individual to the environment,” which “may leave the faculty of the race at a standstill, while the achievements of the race are progressing by leaps and bounds.” * Or, again, he contrasts the progressive evoluticn of the intellectual and moral edifice of society with the cessation of evolution, perhaps even the declining level of “the human builders that contribute in each genera- tion a few more stones to take a permanent place in the fabric.” + * «Wabit and Instinct,” London, 1896, p. 340. t doc, p. 345, Cis) This great edifice was founded on oral tradition. Later on written tradition, and still later printed tradition took its place. When society comes to depend upon the one it in large part ceases to depend upon the others, and in changing its methods it is itself changed. Contrast, for instance, the period in the life of each one of us when we ceased to remember the affairs of daily life and gave our memory into the keeping of ink and paper. Although much was gained in the inevitable change, something was lost. Until recently there have been many people in this country, there are probably a few now, who, unable to read or write, can remember the details of complicated accounts in a manner astonishing and impossible to those who possess these accomplishments. We see that when society in any age has come to depend upon printing it will be through printing and not in other ways that it will contribute its chief share to the social edifice; and this is not a mere truism, for that age will have lost in large measure other powers which would have been developed in earlier ‘times, powers which would still develop if printing did not exist. Our American friends who enter so thoroughly into the essentials of a subject whenever they direct their attention to it, have not, so far as I am aware, made any determined attack upon this problem. Indeed, the majority of the scientific works, which they so freely and generously place at the dis- posal of students in other lands, are printed upon material,—I will not call it paper,—constructed of the felted fragments of wood, or of a thin paper backing overlaid and loaded with china-clay. The latter class are abnormally heavy, the former abnormally light. This is a matter so important that it ought not to be left to the President of your Society to sound the warning. It is a matter which it would have been well if the Royal Society or the British Association had taken up years ago. It is not creditable to have left to our artist brethren a subject of such paramount importance to ourselves ; for to them belongs the honour of having made the only serious attempts to improve our practice and to call attention to the evil. To the trades concerned I would say that it is strange want ( 10 ) of enterprise to continue methods and use materials which only require to be thoroughly understood to insure a swift and sudden collapse for all but the most ephemeral purposes. I know no producer, scientific or other, whose self-respect would suffer the employment of materials, however good the effect, however low the cost, which would not last over so brief a period as five-and-twenty years. I desire to thank Mr. Horace Hart, Controller of the Oxford University Press, and Mr. J. W. North, A.R.A., for the kind manner in which they have freely given information on this most important matter. I now pass to the subject of my Address :— “THE BEARING OF THE’ STUDY OF INSECTS UPON THE QUESTION, ‘ARE ACQUIRED CHARACTERS HEREDITARY!’ ” To those who incline to criticize the subject of this Address as a raking of the embers of a dead and almost forgotten fire, I would reply that the controversy which sprang into sudden flame—in this country in the year 1887—is still a great memory. I trust that it will ever remain as a great memory. Of August Weismann it has been well said that “he awoke us from our dogmatic sleep.” He made us realize that cherished convictions upon fundamental questions were based on nothing more solid than assumptions, and thus administered the most stimulating shock that has been received by the biological world since the appearance of the “Origin of Species.” It was impossible that a controversy of this magnitude could be conducted without frequent appeals to the Insecta. Their structures, functions, and instincts offered evidence so striking in character, and upon a scale so vast, that discussion was inevitably attracted again and again towards this centre. Indeed, the controversy would have been but one-sided, the conclusion unconvincing, had it been otherwise. At the same time discussion is and must be free and, being free, is almost necessarily scattered. To attempt therefore to disentangle from the mass and to present as a whole the evidence offered by the study of insects is of value in two ways. First, we are made to realize the importance of our study : by the contem- Get} plation of its relation to one majestic example we are prepared for the belief that our subject is essential for the solution of all the widest and deepest problems concerned with organic nature asa whole. Secondly, the attempt for the first time to mar- shal the whole of the evidence supplied by the study of insects will make it possible to strengthen and amplify certain parts, and thus render the whole fabric better balanced and more stable. I should wish at the outset to express my indebtedness to the columns of ‘ Nature,” by means of which nearly the whole of the controversy has been followed, We are happy in the possession of a single journal in which discussions on general scientific questions are, by common consent, carried on. “ Acquired Characters” defined.—Before beginning a dis- cussion it is important to remove any possibility of doubt or uncertainty as to the precise meaning of the terms which are employed. The word “acquired” as used in this controversy has been the source of as much confusion as the word “ mimicry.” Just as almost every one who hears of “ mimicry” for the first time assumes that the word means a power of inten- tional imitation, so the inexperienced think that an acquired character is any new structure which a species has gained in the course of its history. “ Why should we not consider every character acquired as an ‘acquired character’ ?” they not unnaturally ask. And the answer is the same in both cases. Because these ordinary and untechnical words were given a special and technical meaning by the writers of memoirs which have become classical. In spite of all incon- venience both words are, in their scientific use, historic, and we must reckon with the fact that they have a special meaning which differs from their ordinary meaning. Erasmus Darwin was, I believe, the first to use “‘ acquired ” in this restricted sense. ‘‘ Fifthly,” he says, ‘‘all animals undergo transformations which are in part produced by their own exertions, in response to pleasures and pains, and many of these acquired forms or propensities are transmitted to posterity.”* Although Lamarck made a preliminary state- * “ Zoonomia,” 1794. Quoted by Professor H. F. Osborn, ‘‘ From the Greeks to Darwin.” New York, 1894, p. 145. ( 12.) ment of his views on evolution in 1802, the celebrated ‘Philosophie Zoologique” was not published until 1809, fifteen years after the appearance of the ‘‘ Zoonomia,” and it is uncertain whether the author of the later work had ever seen the earlier treatise. Professor Osborn concludes upon the whole that he had not (/. ¢., pp. 152—155). However this may be, the technical use of the words “acquired characters ” is chiefly due to his memoir. The essential passages are the two following Laws of Lamarck :— “ Pyemiére Loi.mDans tout animal qui n’a point depassé le terme de ces developpements, l'emploi plus fréquent et soutenu dun organe quelconque, fortifie peu a4 peu cet organe, le de- veloppe, Paggrandit, et lui donne une puissance proportionnée a la durée de cet emploi; tandis que le défaut constant d’usage de tel organe, l’affaiblit insensiblement, le détériore, diminue progressivement ces facultés, et finit par le faire disparaitre.” “ Deuxieme Loi.—Tout ce que la nature a fait acguérir ou perdre aux individus par Vinfluence des circonstances ot leur race se trouve depuis longtemps exposée, et par conséquent par Vinfluence de l’emploi prédominant de tel organe, ou par celle dun défaut constant dusage de telle partie, elle le conserve par la génération aux nouveaux individus qui en proviennent, pourvu que les changements acquis soient communs aux deux sexes ou 2 ceux qui ont produit ces nouveaux individus.” * Opposite to the characters which Lamarck spoke of as “acquired” are the characters which may be called con- stitutional, congenital, genetic, inborn, innate or inherent. Other names have been specially proposed in order to render apparent the distinction between these two classes of characters. Weismann employed terms which set forth their different origin. The inherent he called blastogenic, expressing an origin that lay far back in germ-cell from which the individual arose. Acquired characters he called somatogenic, to express a later origin due to circumstances which had affected the body-cells. ’ * “Philosophie Zoologique,” tome i. p. 235, Edition Savy, 1873: quoted by Professor E. R. Lankester in ‘‘ Nature,” vol. xli, 1890, p. 415. There had been a tendency in the discussion on this subject to protest against the restricted application of the word ‘‘acquired,”’ and it was assumed that the use was quite recent, and in fact due to Professor Weismann himself. Professor Lankester shows the error of this assumption. (13) The word centrifugal suggests characters developing from within rather than as impressed from without: centripetal conversely suggests characters impressed upon the individual from without, characters which are not the outcome of internal causes.* Acquired structural changes have also been spoken of as modifications, the term variation being restricted to char- acters of germinal origin. All the terms suggested for these two classes of characters convey something of a definition. Thus the brief convenient definition of acquired characters as “those modifications of bodily structure or habit which are impressed on the organism in the course of individual life” { is obviously suggested more or less completely by one set of terms, and “those characters or properties with which the individual is originally endowed” § by the other set. Another attempted definition of an acquired character is as follows :—‘‘ Whenever an organism reacts under an external force, that part of the reaction which is directly due to the force is an acquired character.” || And although it may be impossible entirely to unravel the one part from the other, certain elements may easily be discriminated. For instance, the starting of the reaction as contrasted with the sequence of events which make up the reaction itself is obviously an acquired element, and those who maintain the hereditary trans- mission of acquired characters are required to prove that a reaction which can only be started by an external force in the parent, starts without this stimulus in the offspring. We owe another definition to Mr. Francis Galton :—“ Char- acters are said to be acquired, when they are regularly found in those individuals only, who have been subjected to certain special and abnormal conditions.” * * Professor Lloyd Morgan’s definition conveys nearly the same idea :—‘‘ When the complex of stimuli, which constitute the normal environment, are sufficiently altered (to upset that * “Theories of Heredity,” in the ‘‘ Midland Naturalist,” Nov. 1889. + Prof. J. Mark Baldwin, ‘‘A New Factor in Evolution,” in the ‘American Naturalist” for July 1896. } Professor C. Lloyd Morgan in Baldwin’s “‘ Dictionary of Philosophy and Psychology,” New York, 1901, vol. i, p. 10. § E. S. Goodrich, 7. ¢., p. 10. | ‘‘ Nature,” vol. li, 1894, p. 55, Ts ee aa ( 14 ) balance established between environment and innate qualities resulting in the production of a normal individual) to produce an appreciable change, such a modification or ‘ difference’ may be called an acquired character.” * Such results of abnormal conditions undoubtedly supply extremely striking examples of acquired characters, but it is, I submit, a mistake to make too much of abnormality, or to import it into a definition. Some of the most marked and certainly the most easily studied and tested of acquired char- acters are the differences between the effects of alternative environments, all of which are normal, upon the individuals of a single species. The green colour of a larva of Amphidasys betulavia, if fed upon broom, is an acquired character, as is the dark colour it would assume wpon oak, ete. I think there- fore that a more satisfactory definition of at any rate a large class of acquired characters may be framed as follows :— “Whenever change in the environment regularly produces appreciable change in an organism, such difference may be called an acquired character.” Sir Edward Fry has objected to Mr. Galton’s definition ,—and his objection would equally apply to that which I have sug- gested above—that “the possibility of inheritance is excluded by the definition, and the inquiry whether acquired characters are inherited is impossible.” 7 This appears to me to be only a verbal difficulty. Before attempting to prove whether a certain class of characters can be inherited, it is essential to be able to decide whether a given character which it is proposed to test belongs to the class. If a satisfactory criterion can be reached we can proceed with the test even though the name “acquired” be by our defini- tion denied to the character after transmission by inheritance. The interest of the result would remain all the same. If the character were there—appreciable, measurable,—the effects would be incalculable in their importance, and would not be diminished one iota by the consideration that the name would no longer apply. Sir Edward Fry’s criticism does indeed * PBaldwin’s ‘‘ Dictionary of Philosophy and Psychology,” p. 10. + “Nature,” vol. li, 1894, p. 198. See also Professor Lankester’s reply to the criticism, on p. 245, (5) suggest a change—and I think a desirable change—in the statement of the problem. For the question, “ Are acquired characters hereditary?” it would be more accurate to sub- stitute ‘‘Can the acquired characters of the parent be handed down as inherent characters in the offspring ?” It is in no way necessary that the acquired elements of a character should be disentangled from the inherent elements, so that we can prove the character as a whole to be dependent upon a controllable external cause, and therefore itself con- trollable. In fact we speak of a character as “acquired” just as we speak of an article as “manufactured,” although the result itself is a complex of the properties of natural substances and of changes introduced by art.* Lamarck’s Second Law a contradiction of his First Law.— Before leaving these general introductory considerations and proceeding to weigh the evidence offered by the insect world, it is of importance to demonstrate that there is an in- consistency in the teaching of Lamarck and his followers which, startling as it is, was never noticed until pointed out by Professor E. R. Lankester in 1894.7 “ Normal conditions of environment have for many thou- sands of generations moulded the individuals of a given species of organism, and determined as each individual developed and grew ‘responsive’ quantities in its parts (characters) ; yet, as Lamarck tells us, and as we know, there is in every individual born a potentiality which has not been extinguished. Change the normal conditions of the species in the case of a young individual taken to-day from the site where for thousands of generations its ancestors have responded in a perfectly defined way to the normal and defined conditions of environment ; reduce the daily or the seasonal amount of solar radiation to which the individual is exposed; or remove the aqueous vapour from the atmosphere ; or alter the chemical composi- tion of the pabulum accessible; or force the individual to previously unaccustomed muscular effort or to new pressures * For an interesting discussion on the relation between ‘‘ acquired ” and ‘‘ genetic” characters see Adam Sedgwick’s Presidential Address to Section D of the British Association at Dover (Report 1899, pp. 759-766). t “‘ Nature,” vol. li, 1894, p. 102. ae and strains ; and (as Lamarck bids us observe), in spite of all the long-continued response to the earlier normal specific conditions, the innate congenital potentiality shows itself. The individual under the new quantities of environing agen- cies shows new responsive quantities in those parts of its structure concerned, new or acquired characters. “So far, so good. What Lamarck next asks us to accept, as his ‘second law,’ seems not only to lack the support of experimental proof, but to be inconsistent with what has just preceded it. The new character, which is ex hypothesi, as was the old character (length, breadth, weight of a part) which it has replaced—a response to environment, a particular mould- ing or manipulation by incident forces of the potential con- genital quality of the race—is, according to Lamarck, all of a sudden raised to extraordinary powers. The new or freshly- acquired character is declared by Lamarck and his adherents to be capable of transmission by generation ; that is to say, it alters the potential character of the species. It is no longer a merely responsive or reactive character, determined quantita- tively by quantitative conditions of the environment, but becomes fixed and incorporated in the potential of the race, so as to persist when other quantitative external conditions are substituted for those which originally determined it. In opposition to Lamarck, one must urge, in the first place, that this thing has never been shown experimentally to occur ; and in the second place, there is no ground for holding its oceur- rence to be probable, but, on the contrary, strong reason for holding it to be improbable. Since the old character (length, breadth, weight) had not become fixed and congenital after many thousands of successive generations of individuals had developed it in response to environment, but gave place to a new character when new conditions operated on an individual (Lamarck’s first law), why should we suppose that the new character is likely to become fixed after a much shorter time of responsive existence, or to escape the operation of the first law? Clearly there is no reason (so far Lamarck’s statement goes) for any such supposition, and the two so-called laws of Lamarck are at variance with one another.” These passages have been quoted at length because they Crear |) apply not only to the thought of Lamarck but to those of many modern naturalists as well, and because, so far as I am aware, no attempt has been made to meet the objection. In its most condensed form the argument may be stated thus :— Lamarck’s “ first Jaw assumes that a past history of indefinite duration is powerless to create a bias by which the present can be controlled ; while the second assumes that the brief history of the present can readily raise a bias to control the future.* I now pass to the discussion of evidence derived from the study of the insect world. I do not propose to multiply examples, but shall be content with a few of those which seem sufficiently well adapted to illustrate the main lines of evidence. They have been chiefly, but by no means invariably, selected from the Lepidoptera. This is merely due to the accident that my experience has been chiefly gained in this Order, and not because the examples are in any way more suitable or convincing than those of other Orders. As regards the most interesting part of the discussion, that relating to instinct, the most striking examples have of course been chosen from the Hymenoptera. The origin of the pupal groove which receives the silken loop in Pierine, ete—If we examine the dorsal surface of such a Pierine butterfly as Pieris brassice or rape it is at once seen that the first abdominal segment is traversed by a strongly marked line parallel with its posterior boundary. ‘This character is so well marked that it presents all the appear- ance of a morphological feature. A study of the living suspended pupa shows that the line is formed by the approximated lips of a groove which receives the silken loop or “‘girdle” as it is often called. Longitu- dinal vertical sections of the dorsal cuticle are of course transverse to the line, and reveal the fact that the bottom of the groove is specially thickened. Here was a feature at first sight strongly suggestive of the mechanical effects of linear pressure, pointing to an origin in a kind of mutilation performed by the silken cord upon the soft freshly-exposed surface of the pupa. When I found that removal of the loop * “* Nature,” vol. li, 1894, p. 127. Vise} before pupation, but after the period at which the larva could spin another, did not alter the normal appearance of line and groove in the resulting pupa, I was for the moment convinced that acquired characters are hereditary. But fortunately the inquiry did not come to an end at this point. It was observed that the Pierine pupe which furnished the material for experiment (P. brassice or P. rapx) invari- ably suspended themselves either horizontally or vertically with the head upwards,—never vertically with the head down- wards. Several larve of P. brassicx had fixed themselves in the normal vertical position preparatory to pupation, upon a sheet of glass. Before pupation, but after the period at which the larve could fix themselves afresh or indeed make any attempt to spin, the glass sheet was rotated through half a circle, so that all the larvee came to be suspended head down- wards. In this position they were compelled to pupate. The condition of the resulting pup clearly refuted the hypo- thesis of a mechanically-created groove and thickening, caused by the cutting into and pressure upon the soft yielding cuticle. For in the vertical position with head downwards the pupa slips through the silken loop beyond the position of the groove, so that the pressure has to be borne by an unprepared part of the cuticular surface. Upon the mechanical hypothesis, we should expect that the fresh surface would gain some measure of resistance from the strain; but on the contrary the pup were all hopelessly deformed and the imagines,—if indeed they could have emerged at all,—would have been incapable of flight.* It is evident that from the very begin- ning the loop has been accompanied by a suflicient strengthen- ing of the part of the surface exposed to its pressure as soon as the larval skin was thrown off. The silken loop together with the attachment of the pos- terior extremity of the pupa is in all probability the persistent trace of a vanished cocoon, and we may imagine the selective process which made good each step on the road of gradual * This experiment has not been published hitherto. It was however described and the pup exhibited in the discussion in Section D of the British Association at Manchester, on Monday, Sept. 5, 1887. See Report, p- 755. ( 19) transformation. A cocoon is one form of passive defence, cryptic colouring is another, although the two are commonly combined, especially in cocoons built to endure for comparatively long periods, including the times of special stress,—the winter of the northern belt, the dry season of more southern latitudes. The original decline of the cocoon was probably favoured by a short pupal period falling wholly within the time of least stress,—summer or tne wet season. When the cryptic colouring of the bare pupal surface is as effective for con- cealment as that of the cocoon, it presents certain advantages over the latter. The secretion of a large quantity of material is unnecessary and tell-tale movements in the period before pupation are greatly reduced. These benefits are conferred when the concealment afforded is equal ; but the pupal cuticle lends itself to certain forms of cryptic defence much more freely and completely than the walls of the cocoon :—to the production of angular shapes and of smooth or polished surfaces, to the attainment of varied colours and the perfect gradation of tints, above all to the power of individual colour- adjustment. This latter culminating effort of adaptation—so commonly possessed by larvee and exposed pupze—is apparently extremely rare in the cocoon. Indeed the only positive evidence of its existence is supplied by Hylophila (Halias) prasinana,* and even in this case it would be satisfactory to repeat the experiments on a far larger scale than has been as yet attempted. The transition is easy from a loose and open cocoon with apertures through which the cryptic colours of the enclosed pupa could play their part in defence, through stages in which the latter element becomes more and more important as the cocoon progressively diminishes, to the climax when the almost invisible remnants of the silken covering are retained as supporting structures merely. In all except small and light pups a point would be reached, at a greater or less distance from the climax, when some special strengthening of the cuticle exposed to the strain became the indispensable condition of further advance. Thenceforth further reduction and further strengthening would proceed together, the existing groove and thickening being but the * Trans. Ent. Soc. Lond., 1892, pp. 448-451. ( 20 ) concentration of the broader band of pupal tissue specially prepared to meet the pressure when it first became a danger. Comparison with the pup of some of our common British Geometrz supports the hypothesis set forth above; for it is seen that very similar changes have independently occurred, and occurred so recently that the essential stages are still preserved. Furthermore, they are invariably met with in species which have a short pupal period passed in the warmer months of the northern year. Hugonia quercinaria spins a loose and open cocoon, within which the chrysalis, as well as the larva before pupation, develops an effective cryptic colouring.* Both larva and pupa are freely exposed to view through chinks in the scanty network and between the imperfectly united leaves. Uvropteryx sambucaria con- structs a slight hanging cocoon, affording very little con- cealment. The enclosed pupa bears a marked cryptic appearance, while the only experiment which has been made indicates the possibility of a well-developed power of individual colour adjustment.t Both these species, and especially the last, have long since reached the stage at which the reduction of the cocoon became advantageous. In the genus Zonosoma (Lphyra) we independently arrive at the same climax of reduc- tion attained in the Pierinz, etc., the cocoon being represented by a supporting loop and the means of fixation of the posterior extremity.{ No search has been made, so far as I am aware, for a special strengthening of the cuticle upon which the loop presses, but it is probable that nothing of the kind is required by these small light pupe. The exposed Ephyrid chrysalis is fully as cryptic as that of the average butterfly, but it lacks the power of colour adjustment. When the Ephyrid larva is dimorphic, green or brown, the colour of the pupa corresponds to that of the larva from which it developed.§ * Trans. Ent. Soc. Lond., 1885, p. 319. + See ‘Colours of Animals,” London, 1890, pp. 111, 112. Only one example was placed on white paper before pupation. Although the resulting chrysalis was very pale and strikingly different from the ordinary appearance, the evidence is quite insufficient, and it is much to be hoped that the experiment will be repeated upon a large scale. + Trans. Ent. Soc. Lond., 1884, p. 57. § Trans. Ent. Soc. Lond., 1884, p. 51; Phil. Trans. Roy. Soc., vol. 178 (1887), B., pp. 487, 438. Such correspondence has not been observed in any other Lepidopterous insect. If we take into account the fact that Zonosoma (Ephyra) is a characteristic Geometrid genus, although its method of pupal suspension is unique in a family whose species make cocoons or bury, we may feel confident that it has been descended from cocoon-making ancestors, and that Hugonia quercinaria and Uropteryx sambucaria give us a clear idea of the steps by which the reduction was effected. The effect of Gravity upon the shape of suspended pupx such as those of the Nymphaline.—Kvery naturalist who has watched the pupation of a Vanessid must have observed the extraordinary mobility of the abdominal region of the freshly-expored chrysalis. Movements of remarkable ampli- tude take place in every direction, and especially in the dorso-ventral plane, these latter being essential for the with- drawal of the posterior segments from the larval skin and the remarkable feat of attachment to the silken boss close to the point from which the skin itself is hanging. Success is only rendered possible by the remarkable contractile power of the intersegmental muscles along the median ventral area. These, by their contraction, keep the rigid hook-armed apex of the abdomen firmly pressed to the outside of the larval skin up which it is being forced, and enable it to press down or push aside any of the stiff spines which oppose the move- ment: these finally bring it to the small silken boss which alone provides a secure basis of attachment for the terminal hooks. For this purpose the ventral muscles require to be far stronger than those of any other region, and we invariably find that they entirely overbalance the dorsal intersegmental muscles in pup which have been produced on the floor of the breeding-cage. In such pupe the abdominal segments are curved round towards the ventral side, so that the long axis of the apical part forms at least a right angle with that of the thoracic region, and this attitude becomes stereotyped with the hardening of the pupal cuticle and the consequent loss of all power of dorso-ventral movement. These free pup forra a striking contrast with the normal attached individuals in which the long axis of the abdominal segments is nearly in the same line with that of the thoracic. Suspension by the posterior apical hooks and the assumption of a form in which the long axis of the body is nearly in one line, is very ancient, dating back to the common ancestor of a number of closely-related species. For a countless number of genera- tions the soft and yielding Vanessid pupa has been subjected to the strain of gravity and has responded by the production of a definite shape, viz. one in which the long axis is parallel with the line of force. And yet not a trace of any hereditary effect is manifest. Remove the strain and the individual is free, unbiassed by the forces exerted upon unnumbered ancestors, to assume an entirely different shape. ' Vanessid pupze alone, so far as I am aware, have been studied from this point of view. Figures of other suspended Nymphaline pup however indicate that all do not yield equally to the strain, although I believe that all are to some extent affected. The pupe of the Argynnide contrast in an interesting manner with those of the Vanessidx in this respect. The strongly-curved pupa of Argynnis aglaia figured by W. Buckler * was probably supported wholly or in part by a leaf, as is suggested not only by the shape but the plane of the surface of attachment, as shown in the figure, and to some extent by the description. Variable Protective Resemblance in Insects——The power which it is now known that many larve and pupz possess of changing their colour into correspondence with the tints of each one of several possible environments has been thought to favour the Lamarckian interpretation of the origin of variation. Thus the late George J. Romanes said of the evidence which had been brought forward to prove the power in question :—‘ It has always appeared to me that the experi- ments themselves are among the most valuable which have hitherto been made regarding the causes of variation,” 7 an opinion due, as the writer states, to his acceptance of the ‘“¢ Lamarckian conception.” On the other hand, I have never doubted that the results are in the nature of a climax rather than a foundation, that * Ray Society, ‘‘ Larve of British Butterflies and Moths,” vol. i, Plate X, fig. 3b, 1886. + ‘‘ Nature,” vol. xxxviii, 1888, p. 364. (eee) they represent the highest achievement of natural selection in. the protective colours of insects. If these variable colours represented the beginnings of ordinary fixed colour variations the species would lose and not gain by the change. The essence of the protective value is the power of being concealed in each of several different environments, and hereditary transmission of the results would only injure the individuals of the next generation. The intricacy of the processes by which the stimulus gives rise to each appropriate colour-effect is no difficulty to the interpretation based on natural selection— ‘fan agency capable of dealing with complex physiological relationships in precisely the same way that it deals with all other kinds of variations.” * The barren conception of “ self-adaptation,’’—the hypothesis that organisms possess a constitution which compels them to react adaptively, breaks down when we find the adaptation is only possible by means of a specialized and complex train of physiological sequences. We must remember that the species we investigate are “heirs of all the ages,” thoroughly inured to experimental research, past masters in the art of meeting by adaptive response the infinite variety of stimulus provided by the environment, If we remember this we shall always be on our guard against a too hasty interpretation based on the fundamental properties of protoplasm.t The hypothesis that organisms are so buiJt that they must produce useful variations, seems to be little more than the old “internal developmental force,” or ‘‘innate tendency towards perfection,” ina modern dress. Furthermore, a consideration of the essential meaning of adaptation proves the futility of any such attempt at explanation. The ultimate object of adapta- tion is to obtain food, to escape enemies, or to subserve reproduction. The most conspicuous adaptations manifested by an individual are relative to the condition of the organic environment with which its contact is in many respects * Professor Meldola in ‘‘ Nature,” vol. xxxviii, 1888, p. 389. See also Professor Meldola’s Presidential Address in Proc. Ent. Soc. Lond., 1896, pp. Ixx, Ixxi; and the first scientifie paper published by him, viz. Proc. Zool. Soc. 1873, p. 153. t ‘‘ Nature,” vol. Ixxi, 1905, p. 244. ( 24 ) irregular, uncertain, or even wanting. Caterpillars are provided with beautiful protective adaptations, but the suc- cessful individual never comes into contact with an enemy. But there is an environment which the organism cannot avoid, —the physico-chemical stimuli of climate and food ; and it is presumably here, in the inorganic conditions of life, that the influences which bear a pre-eminent part in evoking useful variations are supposed to reside. So that stimuli provided by one form of environment are looked upon as the direct causes of adaptations which are essentially related to another and very different environment. * The Instincts of Insects —Those who advocate the hereditary transmission of acquired characters have made great use of the argument that the wonderfully complex and precise adaptive instincts of insects require for their production the accumulation of experience and of effort through many generations. Only by such transmission, they maintain, is it possible to understand such development. It is safest to begin with a definition, and I accept the brief, convenient and in my opinion entirely accurate statement of Lloyd Morgan:—“ Instinct depends on how the nervous system is built through heredity ; while intelligence depends upon how the nervous system is developed through use.” f We observe in the first place that the Lamarckian interpreta- tion places the more difficult phases of the evolution of instinct —the phases when it was not instinct at all but something much higher—in some remote epoch of the past, and at a lower level of progress. In such times, ex hypothesi, the less developed and presumably less efficient brains of insects did by the intelligent use of experience what they now do mechanically by instinct. This is an inversion of the probable course of evolution: the less efficient instrument has assigned to it by far the more difficult task. Apart from this primd facie objection there are solid grounds for the belief that the exquisitely perfect operations of insects with which we are familiar arose as instincts, as * The substance of the argument set forth in this paragraph was published by the writer in ‘‘ Nature,” vol. 1, 1894, p. 445. + “ Animal Behaviour,” London, 1900, p. 120. ( 25 ) instincts were gradually perfected, and that intelligence never came into the history at all. It is not from the insects which have had the most varied experience of enemies, most opportunity of learning by contact with danger how to avoid them, and thus of developing their nervous systems through use, it is not from these that existing forms have been descended, but from precisely those which have had the least experience. Even for ourselves experience is spoken of as “the stern guide.” To an insect she is apt to be so stern as to lose all her educational value. The less an insect sees of her the better the chance of existence and of representation in the generations of the future. The prime necessity for an insect, as for all animals which cannot in any real sense contend with their foes, is to avoid experience of them altogether.* This is an argument with the broadest possible application to all Orders of insects. To the adaptive movements of a beetle which when disturbed falls to the ground, draws in its limbs and antennz, and looks exactly like a little lump of earth ; to the alertness of a fly to take wing before an enemy is within striking distance; to the perfection of all such means of defence in insects, and they are numberless, we may apply the words of Browning :— “*Oh, the little more, and how much it is! And the little less, and what worlds away !” It is all the difference in fact between success and failure, between life and death. Comparatively rarely are the con- ditions of the struggle such as to admit of partial failure or of improvement by experience. One special reason for the passive means of defence adopted by the vast majority of insects is to be found in the peculiar dangers of their structure. Especially is this true of larvee, with their hemolymph contained in freely communicating * This argument was brought forward by the present writer in the discussion on ‘* Are Acquired Characters Hereditary ?” at the meeting of Section D of the British Association, at Manchester, Sept. 5, 1887 (Report, p. 755). No part of the discussion is published, The argument is however briefly stated in Proc. Boston Society of Nat. History, vol. xxvi, 1894, p. 391, and also quoted in ‘‘ The Zoologist,” Dec. 1900, pp. iayil, tase ( 26 ) cavities, and subject to the pressure of muscular body-walls. Hence an insignificant injury may often cause death or imper- fect development from the quantity of fluid which is lost. “Tt is, I believe, in consequence of these facts that the various means of protection in larvee are almost always of a passive kind... . Nearly all the means of defence against... enemies [other than ichneumons, etc.] are such as tend to prevent the larva from being seen or touched, rarely such as to be of any avail when actually attacked. There may be various changes in the mode of defence, but the object is always the same—to leave the larva untouched, a touch being practically fatal.” * Let us consider for a moment the mental operations involved in the act of profiting by experience. Consider, for instance, Mr. A. H. Hamm’s interesting observation—since abundantly confirmed by the testimony of many naturalists—that the vast majority of the individuals of Hybernia leucophexaria rest with the body horizontal, thus bringing the lines of the wings into parallelism with the dark shadows in the vertical cracks of the oak-bark.+ Anindividual which adopted a different attitude and rested so as to cause the main lines of its pattern to cut the main lines of its environment might indeed escape by flight ; but can any one really believe that a moth, or any of the ancestors of moths, could associate the special disturbance and danger to which it had been exposed with the special attitude it had assumed, and would as a result of that associ- tion begin to make changes in its attitude? It is easy to speak of improvement by experience, perhaps easy to think of the progress of an insect’s education under the sternest of teachers: easy so long as we confine ourselves to generalities. Attempt to picture the process in a definite case, and apply it, as I have done, to account for the growth of some special protective adaptation, and it is instantly borne in upon us that we are placing on insect psychology a load it is altogether unable to bear. The Cocoon-making Instinct.—There are however number- less examples in which it is impossible that improvement could * Trans. Ent. Soe., London, 1885, pp. 321-323. + Proc. Ent. Soe, Lond. for March 19, 1902, p. xv. ( 27 ) be thus effected, even if insects did possess the requisite brains, that is unless we also accord to them the gift of prophecy. These are the cases in which instinct prepares for the dangers of a struggle at some future time, when the organism which manifested the instinct will have changed its form, and become incapable of making further changes in the means of protection, and indeed as a rule entirely incapable of making any defence. Consider, for example, another observation made by Mr. Hamm in July 1900, upon the cocoons of Malacosoma neustria spun within the leaves of black-currant and apple in his garden at Oxford. These he found to be opened by birds, probably sparrows, which had pecked a hole in the leaf, thus breaking through the cocoon at its thinnest point,* and abstracted the chrysalis. A still more convincing example is to be found in the origin and maintenance of the instincts involved in the con- struction of a freely exposed yet admirably concealed cocoon on bark. Think of the natural cracks just filled up, of tunnels closed flush with the surfaces around, of the resemblance to excrescences or ridges which appear perfectly natural upon bark. Considering not only the forms but the colours and texture of the external surface, we recognize at once that such structures are the product of a highly perfected group of instincts. At first sight indeed the case seems to prove too much ; for it may be thought that such cocoons are so completely hidden as to defy the sharpness of any enemy however acute, and * The cocoons were exhibited to the Society on March 19, 1902. See Proc. Ent. Soc. Lond. 1902, p. xv. Mr. W. Holland many years ago showed that birds attack in this particular way, but his observation was upon larvze spun between leaves, and not pup ; and the latter are specially suited for enforcing the present argument. Mr. Holland’s observation is as follows :— ‘On the 6th of this month [June 1890, near Reading] Captain Robert- son and I went to get:some larvie of populeti from some low trees of Populus tremula which were covered with that species. Captain Robertson had picked off about 100 larve the night before ; but this morning, when we arrived at the trees, we found some starlings had also discovered the caterpillars, and had gone over the trees systematically from branch to branch, peck- inga hole in one side of the spun-together leaves, and drawing out the caterpillar, and so nearly had they cleared them all off, that we had much trouble to find a dozen. We caught the birds in the act, and although they had so nearly finished their feast they were very unwilling to go, and loudly objected to our disturbing them,”’—‘‘ Entomologist’s Monthly Magazine,” 1890, p. 216, 8) believers in natural selection may properly be asked to bring evidence of the existence of a struggle in which the high elaboration of the instincts in question is a defence. ‘There is no difficulty in meeting the challenge, for specially directed observation at once reveals the existence of a keen struggle in which the concealment of the cocoon is the criterion of life or death. My attention was first directed to this particular aspect of the struggle for existence in insects, on April 12, 1893, when I found on the bark of Populus nigra, near Yoxford, Suffolk, a cocoon of Dicranura bifida which had been opened by some enemy, and the pupa removed. The observation is, I believe, a common one, in fact Commander Walker and Mr. Holland inform me that it is usually difficult to find cocoons of this species which have not been thus attacked. Nevertheless, for the sake of those who have not had the experience, I think it is worth while to re-describe the evidence which certainly justifies us in inferring that ‘an enemy hath done this.” “The edges of the opening were still brown and fresh, as was the interior of the cocoon; and the larval skin remained fresh and untouched inside. The opening was in the middle of the exposed surface and not at one end, as it is when the moth emerges. Besides, the cocoon had been opened and cracked by a blow from some hard object, such as a bird’s beak, and the sharp irregular margins were quite different from those of the natural opening made by the moth, doubtless by means of a corrosive fluid, as in the allied species, Dicranwra vinula, which Mr. O. H. Latter has recently shown to secrete caustic potash for this purpose. Furthermore, the moth emerges far later in the year, and, had it emerged at an exceptional time, the empty pupal skin would have been left behind in the cocoon. We may therefore safely assume that the opening was the work of an enemy, and, as the cocoon was five feet from the ground, it was probably due to some tree-creeping, bark-exploring species of bird. . . . It is probable that the attention of the enemy is directed to any cocoon-like object by the sense of sight, and that the object is then tapped, and, if found to be hollow, opened and the pupa devoured.” * * “The enemies of Lepidopterous pupe enclosed in bark-formed cocoons,” —‘‘ Science,” xxiii, 1894, p. 62. The date of the observation is The cocoons of bifida are spun in the autumn, but the attack did not take place for several months. The example is probably typical in this respect. The procryptic preparation of the autumn is the adaptation by which the average numbers of the species are kept up in spite of ceaseless bark- hunting during the months when the trees are leafless and food is searce. The Lamarckian interpretation fails to account for the cocoon-making instinct for two very sufficient reasons : first, a chrysalis is incapable of learning by experience how to improve anything,—even more obviously incapable of learning concerning a structure which it never makes. Secondly, however intelligent a chrysalis may be, the experience itself is of such a nature that its stores of learning cannot be handed down to posterity.* If the Lamarckian interpretation of the cocoon-making instinct must inevitably fail, as I think we shall agree it must, what is there to put in its place? Those who believe in the efficiency of Natural Selection in evolution will probably regard the instinct of building these beautifully-adapted structures as the outcome of countless generations during which the attacks of enemies have been, on the whole, more successful against the products of less perfected instincts and less so against those of the more perfected. They will further suppose that the increasing perfection in instinct has acted selectively on enemies, sharpening their faculties, until, by action and reaction, the present high level of constructive skill has been reached, and is maintained. The Instincts of the Hymenoptera.—No discussion of instinct would be in any way complete without a consideration of the most wonderful examples of all, viz. those manifested by the Hymenoptera. The instincts of the Fossorial Aculeates in providing for their larve, studied with all the sympathy of a born naturalist and described by a master of style,—have erroneously given as the year of issue instead of 1893. Some of the later sentences of the same communication are also quoted with slight modification on the present occasion. * This argument also is briefly stated in the ‘Proc. Boston Soc. Nat. Hist.,” vol. xxvi, 1894, p. 391, and quoted in ‘‘The Zoologist,” Dec. 1900, pp. 951, 552. ( 30 ) formed the foundation of a gigantic speculative edifice. The controversy has in reality been a three-sided one. I, First, we have Fabre disbelieving in evolution altogether, and adducing evidence that his favourite insects have not gained their wonderful instincts by progressive change pointing out that they perform their duties under some stimulus which to them is imperative, whether the object of their pains be achieved or not: arguing, for example, that in those that feed their larve from time to time, the stimulus to enter and deposit the insect food is not the young larva itself but the door of the tunnel. II. Secondly, Lord Avebury and the late George J. Romanes have argued in favour of evolution by a gradual education, finally inherited as instinct. There is reason to believe that Darwin accepted the same view. He certainly never opposed it. Lord Avebury alludes to the letter written to Fabre, in which Darwin “refers to the great skill of the Gauchos in killing cattle, and suggests that each young Gaucho sees how others do it, and with a very little practice learns the art.” * Lord Avebury identifies himself with this view, which, indeed, he had himself set forth in the “Contemporary Review,” in 1885. Concerning the instinct of the Ammophila to sting the ganglionic centres of its caterpillar prey, he suggests that “during these long ages they may have gradually learnt the spots where their sting would be most effective, and .. . so have gradually acquired their present habits.” + He finally con- cludes that “these remarkable instincts ” are ‘‘the result. of innumerable repetitions of similar actions carried on by a long series of ancestors.” { George J. Romanes in reviewing Lord Avebury’s book goes much further :—‘“ Here, by the way, we have an excellent instance of the dificulty which we so often encounter in the domain of instinct, when we relinquish the so-called Lamarckian principle of the inheritance of acquired characters. The hypothesis in question goes upon the supposition that * Sir J. Lubbock, ‘‘On the senses, instincts, and intelligence of animals, with special reference to insects.” London, 1888. Internat, Sci. Ser., p. 248. t p. 248, Tt p. 252, ( 3) some of the ancestors of the Sphex were intelligent enough to notice the peculiar effects which followed upon stinging insects or caterpillars in the particular regions occupied by nerve- centres, and that, in consequence of being habitually guided by their intelligence to sting in these particular regions, their action became hereditary, ¢.e. instinctive. But if, in accord- ance with post-Darwinian theory, we relinquish this possible guidance by intelligence, and suppose that the whole of this wonderful instinct was built up by natural selection waiting for congenital (¢.e. fortuitous) variations in the direction of a propensity to sting, say, the nine nerve-centres of a caterpillar —then it surely becomes inconceivable that such an instinct should ever have been developed at all.” * Eimer is even more rash in his statements :—‘“This is one of the most marvellous instincts that exists ; since the wasp operates on various larve with nervous systems of various forms, she must effect the paralysis in various ways, and even apart from this, she makes a physiological experiment which is far in advance of the knowledge of man. ... It may be suggested that the wasp only paralyzed the larve in order to carry them more easily; but even if this were the ease, she must, since she now invariably acts in this way, have drawn a conclusion by deductive reasoning. In this ease it is absolutely impossible that the animal has arrived at its habit otherwise than by reflection upon the facts of experience.” Mr. and Mrs. Peckham make the following comment upon this wild passage from Eimer :—“ One can hardly be expected to take such statements seriously, since it is certain that the writer has no knowledge of the life-histories of these insects.”’ } Ill. Thirdly, there are those who believe that the instincts in question are to be explained by the operation of natural selec- tion upon hereditary nervous mechanisms, who believe that the Lamarckian principle of the hereditary transmission of education has never come into the history at any stage. Fabre’s observations are quite consistent with this view; in * Nature,” vol. xxxix, 1888, p. 77. + ‘*The Instincts and Habits of the Solitary Wasps,” by George W. and Elizabeth G. Peckham, Madison, Wis., 1898, p. 22). ( 32 ) fact it would almost appear that Darwinian evolution as apart from Lamarckian evolution is really unknown to this great naturalist. He seems invariably to strike Lamarck when he aims at Darwin. In this however he is only acting in the same manner as the majority of the early critics of the ‘Origin’, * In attempting to decide upon the past history of these insects the first necessity is to be sure of the facts. Fortu- nately the ground has been re-traversed by Mr. and Mrs. Peckham, so that we can compare the observations of great and keen naturalists in two hemispheres. We find that by the study of nine wasps of an American species, A. wrnaria, of the very genus Ammophila, which, as previously described, chiefly furnished the basis of speculation, the American naturalists have shown that the immense superstructure is in large part due to a fertile imagination. So far from the assumed perfection and accuracy with which every detail is supposed to be repeated, the instinct is shown to be excessively variable. The frequently-quoted conclusions that the object of the sting is to reduce the larvee to helplessness and yet keep it in a fresh condition, that a dead larva would he unsuitable food and an active one a danger to the offspring of the wasp—all these conclusions are entirely disposed of by a few careful specially directed observations. These show that the larva rapidly dies in a large proportion of cases and yet affords excellent food, and that it may remain sufticiently uninjured to wriggle continuously without stimulation, and to move violently when bitten by the larva of the wasp.+ The following activities or performances are regarded as truly instinctive, viz. as due to the compulsion of a hereditary nervous mechanism :—Stinging, the methods of attack, cap- ture and carriage of prey peculiar to each species, the kind of prey selected, the general style and situation of the nest, the form of cocoon. } The American naturalists finally conclude their volume with these words :—‘ The general impression that remains with us * ¢*Proe, Boston Soc. Nat. Hist.,” vol. xxvi, 1894, pp. 377—379. See also Poulton, ‘‘Charles Darwin and the Theory of Natural Selection,” London, 1896, chapters xix, xx, pp. 144-160. Tt 7.¢., pp. 30, 3. i Uc., p. 234. (y22"4) as a result of our study of these activities is that their com- plexity and perfection have been greatly over-estimated. We have found them in all stages of development and are con- vinced that they have passed through many degrees, from the simple to the complex, by the action of natural selection. Indeed, we find in them beautiful examples of the survival of the fittest.” * As long ago as 1889 the present writer had argued that the Lamarckian interpretation of the instincts of Ammophila or Sphex introduced the same difficulty as that alluded to in the discussion of the cocoon-making instinct. It implied a gift of prophecy, a knowledge of what would happen to offspring after the burrow had been sealed and left to its fate. Another powerful argument is derived from the comparison between the instincts which are performed but once and those which are performed many times in a single life. Various elaborate performances are undertaken but once in an insect’s * See the review of Dr. and Mrs. Peckham’s work in ‘ Nature,” vol. lix, 1898, pp. 465-468. , + The argument was used in the ‘‘ Discussion on Acquired Characters ” in Section D of the British Association at Newcastle, Friday, September 13, 1889. See Report, p. 620, where, however, only the title of the paper is printed. The following sentences are quoted from the abstract in ‘** Nature,” vol. xl, 1889, p. 610 :— ‘‘ With regard to instinct, Dr. Romanes had suggested a difficulty— that was, the instinct of certain wasps to sting and paralyze the nerve centres of their prey. But it must be remembered that the benefits arising from this instinct were felt not by the wasps themselves, but by their progeny.” In ‘Proc. Boston Soc. Nat. Hist.,” vol. xxvi, 1894, p. 392, the argu- ment is stated in greater detail as follows :— “The wasp-like insect has no opportunity of learning by experience because it can never know whether the larva stored up is a failure or a success. Ifthe larva had not been stung, or, accepting the received accounts, had been stung in the wrong place, it would struggle and perhaps kill the young grub ; or dying of starvation it might dry up and be useless as food. But the Hymenopteron never goes back to inquire. It makes all the difference to the young grubs whether the food provided for them is in an appropriate condition or not, but it makes no difference whatever to the parent insect. The latter seals up the chamber in which its eggs have been laid and never opens it again ; it has no chance of noting the failure or the success of the food it has provided. It is clearly a case like that of the cocoon, which cannot be explained on the Lamarckian theory and must be explained on the Darwinian. And this latter interpretation is easy ; those insects which possessed the nervous mechanism impelling them to provide food in an appropriate condition gave to their offspring the opportunity of surviving and inheriting the same instinct; while others, impelled to perform less efficient actions, were thereby cut off from any representation in the next generation.” The passage has been slightly modified. Lo32 ) lifetime, and thus are always “prior to individual experience.” * The behaviour which leads to the production of an elaborate cocoon or the burial of a larva in its earthen cell is clearly instinctive, and the most convincing evidence would be re- quired—evidence which it is needless to say is entirely lacking —in order to prove that certain insects which perform an act no more elaborate many times in their lives are guided by anything except the compulsion of a “nervous system built through heredity.” | If the cocoon-making instinct has evolved through selection, the comb-making instinct of the social Hymenoptera has surely arisen in the same way and not through the operation of an entirely different set of causes. As a matter of fact I have witnessed the perfection of comb- building “prior to individual experience” and under con- ditions which prevented the worker from profiting by the experience of others. I have seen “the worker of a species of Vespa freshly emerged from the pupa, and the sole perfect insect upon the young comb (the queen-mother having been previously killed), immediately seize upon the broken material of the comb and begin accurately and with exact precision to build up the thin and delicate sides of injured cells containing the living larvee.” } The strongest of all arguments against Lamarckian evolu- tion was advanced nearly fifty years ago by Darwin in the first edition of the “ Origin of Species” ; and here too we see that demonstrative evidence was supplied to the greatest of all naturalists by reflection upon the insect world, and of the part of it which we are now considering. ‘ No amount of exercise, or habit, or volition,” he says, speaking of ants, “in the utterly sterile members of a community could possibly have affected the structure or instincts of the fertile members, which alone leave descendants. Jam surprised that no one has advanced this demonstrative case of neuter insects against the well- known doctrine of Lamarck.” § * For instance, the cocoon-making instinct, already alluded to (see pp. exx-exxili), Weismann has directed particular attention to this argument against a Lamarckian interpretation (‘‘ The Evolution Theory,” London, 1904, pp. 155 et seqq.). + ‘‘Nature,” vol. lxv, 1901, p. 51, The passage has been slightly modified, Rae se tOOs § ‘‘ The Origin of Species,” London, 1859, p. 242. ( 35) It is indeed surprising that Darwin himself, after his own crushing argument against the hypothesis of evolution by inherited experience, should have been willing to admit some tincture of the same principle in other parts of the wide field. If we are perforce thrown upon unaided natural selection for the origin and growth of the most complex and specialized societies of the Hymenoptera, what need have we for co-operat- ing causes of evolution elsewhere ? I conclude this section of my Address dealing with the most remarkable of all nerve-mechanisms of instinct known to us, with the following impressive comparison, made by Professor Lankester, after contemplating the higher forms in which instincts have been replaced by the power of educability. “The character which we describe as ‘educability’ can be transmitted ; it is a congenital character. But the results of education can vot be transmitted. In each generation they have to be acquired afresh. With increased ‘ educability’ they are more readily acquired and a larger variety of them. On the other hand, the nerve-mechanisms of instinct are transmitted, and owe their inferiority as compared with the results of education to the very fact that they are not acquired by the individual in relation to his particular needs, but have arisen by selection of congenital variation in a long series of preceding generations.” “To a large extent the two series of brain-mechanisms, the ‘instinctive’ and the ‘ individually acquired,’ are in opposition to one another. Congenital brain-mechanisms may prevent the education of the brain and the development of new mechanisms specially fitted to the special conditions of life. ‘To the educable animal the less there is of specialized mechanism transmitted by heredity, the better. The loss of instinct is what permits and necessitates the education of the receptive brain.”’ ‘We are thus led to the view that it is hardly possible for a theory to be further from the truth than that expressed by George H. Lewes and adopted by George Romanes, namely, that instincts are due to ‘lapsed’ intelligence. The fact is that there is no community between the mechanisms of instinct and the mechanisms of intelligence, and that the latter are later in the history of the development of the brain than the ( 36 ) former, and can only develop in proportion as the former become feeble and defective.” * The bearing of Insect Warning and Mimetic Colours upon the supposed hereditary transmission of experience by their Verte- brate enemies,—Adaptations which facilitate the education of entomophagous vertebrates are so perfect and so wide-spread in insects that they constitute a large body of indirect evidence in favour of the non-transmission by heredity of the results of experience. Fritz Miiller, in bis celebrated theory of mimicry, suggested that the object of the likeness between the warning colours of specially-protected species was to reduce the danger from the attacks of young and inexperienced enemies. This is all the more interesting because, as Professor Meldola has pointed out, “in 1879 the question of the non-transmission of acquired characters had not been brought into prominence. It was tacitly assumed in the theory of Bates that a know- ledge of edible and inedible types could be transmitted by heredity. It is remarkable that Miiller, by virtue of his hypothesis, should have unconsciously challenged this tacit assumption by suggesting that young birds had to learn by experience, and did not derive their knowledge of eatable and distasteful forms by heredity. The whole tendency of Prof. Lloyd Morgan’s work of late years has been to confirm the suggestion by actual observation and experiment; and Mr. Finn, also, in summing up this result, states that ‘each bird has to separately acquire its experience, and well remembers what it has learned.’ Thus the Miillerian theory of 1879 has now been placed on a psychological basis of well-ascertained facts.” 7 The problem has been attacked from both sides with concordant results. In contemplating the vast scale upon which these aids to memory and education are developed, it is necessary to take into account the pressure of the struggle for existence upon the enemies themselves. ‘This pressure is chiefly felt by the young, and it is so excessive that compara- tively few individuals in the fresh wave sent forth at each breed- ing season, survive to become mature and experienced. It * From the Jubilee Volume of the Soc. de Biol. of Paris, 1899. Reprinted in ‘‘ Nature,” vol. lxi, 1900, pp. 624—625. + ‘‘ Nature,” vol. lx, 1899, p. 57. Cor} follows from this fact that the amount of selective pressure exerted by inexperienced enemies of insects is many times as great as that which is due to the educational period of the mature enemies existing at any moment.”* We also realize the fact that insects as food are of far greater import- ance than might be at first sight supposed ; for they supply not only the insectivorous species but those other forms which in turn prey upon them. Thus, when we bring together the evidence supplied by the study of insects it is seen that it nowhere supports the assumption upon which Lamarckian evolution is founded, the assumption that acquired characters are transmissible by heredity. Before leaving the Chair at the conclusion of my second year of office I desire warmly to thank the Officers, Members of Council, and Fellows of the Society, who by their kind- ness have made my task so easy and altogether pleasurable. You will, I know full well, accord the same generous sympathy to my successor, and under his guidance I feel confident that the prosperity of recent years will be continued, I hope in even larger measure. Before taking leave of the Fellows in my official capacity I desire to direct their attention to two thoughts, both of which I have endeavoured to keep prominently before the Society, thoughts which I trust will continue to inspire our meetings: First, ever to remember the high significance of the material we study; to realize its priceless value for the elucidation and the solution of problems the most intricate, difficult and important ; to feel that this unrivalled opportunity is a serious personal responsibility. Secondly, always to bear in mind that London is a great deal more than the capital of England, and that the Entomo- logical Society of London can do much to help the work of naturalists all over the world—men in some conditions better off than we are, in other conditions less well provided, with new and inspiring problems at hand calling for study, but * Proce. Ent. Soc. Lond. 1903, p. lxv. The form of the passage has been slightly modified. (e887) without the stimulus and the continual aid of our vast stores of literature and our easy intercourse with kindred minds. We can do much to help such men, not only by means of our publications but even more by establishing contact with them, by showing them that their work is of value and interest to the naturalists of a distant land. And although I trust and am sure that such encouragement will be offered freely to every naturalist who may approach us, whatever be his nationality, yet the wide extent of the British Empire and the roving spirit of her sons, ensure that it will be our own people in many lands whom we shall chiefly benefit, who will benefit us in turn. And thus we may hope to aid in no small measure the forces that make for sympathy and friendship and true union between men whose communication is thwarted by both time and space. And this happy result will be achieved by and will itself promote the advancement of that branch of learning for which this great Society came into being, grew into strength and beneficence, and awaits I doubt not a yet more glorious future. XXVI. Protective Coloration in its relation to Mimiery, Common Warning Colours, and Sexual Selection. By Assorr H. THAYER. Communicated by Pror. Epwarp B. Poutton, M.A., D.Sc., F.R.S. [Read October 21st, 1903. ] Tue following paper records an artist’s examination of the principles of butterflies’ coloration, and shows how the results tend to restrict the fields heretofore claimed for Mimicry and Common Warning Colours, and to place them on a basis of Concealing Coloration. It contains also several arguments tending to restrict the hypothesis of Sexual Selection. It does not attack the obvious fact that every possible form of advantageous adaptation must somewhere exist. It is obvious to its writer that there must be unpalata- bility accompanied by Warning Coloration,—as apparently in the cases of the Hornbills and Wood Hoopoes reported by Mr. Frank Finn, and probably in many Corvide, for instance,—and equally plain that there must be Mimicry, both Batesian and Miillerian. Yet every case demands special examination, for the reasons that I shall show herein; and no apparent conspicuousness of coloration is sure to prove such when examined on the principles established in this article. First, it seems necessary to establish the artist’s claim to be the judge of all matters of visibility, and the effect, upon the mind, of all patterns, designs, and colours. If even the artist is limited in this, his own field, what hope is there for others? Fullest wisdom on the part of naturalists would make them adjourn all matters of animals’ appearance to us artists, Just as any wise ruler gathers about him the most highly specialized minds, to widen, through them, his own scope. An artist reads design wherever it occurs, just as a composer reads a score, without playing it, or hearing it. He perceives that every juxtaposition of spots, or shapes, or colours, or of dark and light, and of degrees of these, TRANS. ENT. SOC. LOND. 1903:—PART IV. (DEC.) 554 Mr. A. H. Thayer on is just so much representation of some structure, whether the representation be accidental or intentional. He sees at a glance in marble-veins, the grain of wood, etc., not imaginary, but actual representations of natural objects and perspectives, and weighs the correctness of these. Nature has evolved actual Art on the bodies of animals, and only an artist can read it. When he examines the colour and colour-pattern of the animal kingdom, he sees that zoologists are hopelessly off the track in their general conception as to which coloration is to be called con- spicuous, i.e. rendering its wearer so. Any coloration or pattern would be conspicuous somewhere, and Nature cannot prevent animals from straying beyond the environ- ments that would most perfectly harmonize with their colour and pattern. But let us take the broadest possible survey, and we cannot doubt that most animals wear on their coats pictures of their habitat. As I before pointed out, even the under-sides of the wings and tails of hawks bear the general twig-patterns so common on forest birds, as if Nature found it worth while to efface the white silhouette their wings’ under-sides would make when they extended them while perching. We see how completely such patterns (when couched, of course, as they always are, in the effacive gradation) do help to obliterate a partridge, grouse, woodcock, hare, or any other of almost all the species in every order; since they prove to be actual animated pictures of their environment. As I said before, in my paper on so-called “ Banner-marks,” * these forest- like patterns are found on forest creatures, and not on desert creatures, or ocean creatures. Sand-birds are usually marked in longitudinal, delicate patterns, very like those the sand assumes when seen at the same angle at which one observes the birds themselves. Tigers and zebras are resolved into pictures of tall, strong flags, grasses, and bamboos, while the lion is a picture of the desert. (It will some day be plainly understood that the effacive gradation is the essence of the success of these pat- terns. Were they not arranged to compose one perfect counter-gradation, from top-dark to under-white, they would appear merely as what artists call “lines of quantity,” like the hoops of a barrel, emphasizing the rotundity, not effacing it.) Now, let me prove that any pattern would somewhere be * ©The Auk,’ vol. xvii, 1900, p. 108. Protective Coloration in its relation to Minviery, etc. 555 conspicuous. I once saw a skunk (Mephitis americanus) crossing a snow-field near at hand. This animal is black (with the slight amount of effacive gradation found even in black animals), with a large white pattern on top. He was totally unrecognizable, because his white against the snow was undistinguishable. His black was left to form a most grotesque silhouette. Had he been against black, it would have been this black part that disap- peared, and one would have seen only an unrecognizable, moving white thing. Naturalists’ lack of understanding this principle’s immense import has gone far to strengthen the present Mimicry and Warning-Colour theories, which may prove to have been evolved, largely, in the effort to explain supposed conspicuousness, where such did not exist. A tiger in the desert sands, though his gradation would still, more or less, efface his solidity, would never- theless show his pattern. His bamboo-vistas would be plainly a failure against the sand. The lion in the bamboos would, when not covered by them, tend to present an unac- countable flat silhouette,—a lion-shaped section of desert- landscape, out of place. On the same principle, a white patch on striped cloth or a striped patch on white cloth would be conspicuous. We see on all hands evidence that Nature cannot help moving forward to the utmost com- pleteness of protective devices ;—that, in fact, she cannot grope or blunder. A marvellous, turquoise, emerald-green and red-coral-marked Mediterranean fish looks conspicuous on the fishmonger’s slab; but follow him to the sun-lit ocean grottos which he inhabits, and of which he is a wonderful picture! No, the whole use of the word con- spicuous is mainly born of the zoologist’s lacking the artist’s sight. Let us now turn to the field in which the naturalists are most conspicuously at fault, that of the butterflies and moths. One glance of an artist,—that is, of an artist accustomed to lifelong looking at vegetation and butterfly- life,—at a world’s collection of butterflies, shows him that they are mainly either flying pictures of various com- binations of flowers and their backgrounds, pictures of the shadow under foliage, with delicate patterns of vegetation or flowers drawn across it, as, for instance, in the North American Papilo polydamas, and the dark Satyrinx,—or that they are wonderful representations of flowers them- selves, as in the Pierine (all but their usually narrow dark 556 Mr. A. H. Thayer on border), many of which even bear a representation of six stamens (counting their two antenne), and, what is very common in butterflies, a wonderfully perfect shading on that part of the wings next the body, grading toward it in a way that makes it appear like the bottom of a con- cavity. My photographs of Limenitis (Basilarchia) arthemis show the flower-form, the appearance of the rim of its cup being carried across the butterfly, as in the species of Precis which wear a large, bright semicircular bar, cutting them as the skunk’s white cuts him. I should have placed at the beginning this axiom: Only unshiny, bright monochrome 1s intrinsically a revealing coloration. As soon as patterns begin, obliteration of the wearer begins, as shown in the case of the skunk. Nature does not blunder, and Natural Selection would evolve the monochrome, instead of a patterned surface, were simple conspicuousness her aim. Also, she would, if she used patterns mainly as badges for identification of the wearer, have omitted the delicate subtilties that go to make up the patterns of most butterflies. Let us apply the skunk- lesson to the many dark butterflies which wear more or less bright, clean-cut patterns. As they rest on flowers, their dark matches very closely the shadow-depths between the flowers, especially when seen from above or outside the flower-mass; and, in fact, the delicate general gradation and faint detail existing even in these parts, appear to an artist to represent the near vistas under the flowers; while the bright pattern is likely to echo the notes of the flowers themselves. Only artists understand this colour- echoing. The artist’s sight is conscious, as it ranges over a scene, of every recurrence of each colour-note. This colour-note, wherever seen, seeks, as it were, ifs own, in his brain,—just as a violin-string rings when its note is sung. In a book we are writing on protective coloration, my son and I shall show larve that resemble things (already well known), larve that disappear, larve that appear to be extensions of leaves; and larve with many other startling and dissimilar concealment-schemes. What wonder if in butterflies there prove to be as many different forms of concealment? It is impossible to lay too much stress on the fact that all patterns which look so striking and bizarre, when off duty, are, when on duty, up to the moment of detection, precisely the workers of the magical illusion that conceals. It is inconceivable that birds should Protective Coloration in its relation to Mimicry, etc. 557 more easily recognize minute patterns than colour, when we realize that the perfect colour-adaptation of innumerable forms of life, from mammals to larve, proves that the lower animals see colour (since otherwise such adaptation would not be necessary for their concealment). In each form of protective coloration there exist cases so pronounced as to leave no doubt of their use. Each of these has been assumed to be mimicked, or, at least, echoed, for some reason, by other species than the one in which it is most perfect. Let us look at the dead-leaf pattern, z.¢. the pattern that represents, in the most minute degree, substance of the colour and thickness of dead leaves, and lying as near the ground as dead leaves usually lie. This pattern is marvellously perfect on the Copperhead snake (Trigonocephalus contortriz), on some Boas, on that form of domestic cat which has the most tiger-cat-like black and grey pattern (as well as, in fact, on tiger-cats them- selves), and on several Sphinx moths. Of course, when this leaf-representation occurs on the rotundity of animals’ bodies, as in the cats or snakes, it exists only in co-operation with the regular effacive gradation, but on the flat plane of a Sphinx’s upper-wing-surface it has and needs no such co-operation. In the Sphinx-moth photograph which I have sent Professor Poulton, this reproduction of thin material casting a shadow on the surface it lies on is past all mistaking. This artifice is present on many moths, and its elements are traceable in such butterfly genera as Vanessa, Grapta, and many others. To know at what point in the long series of somewhat similarly marked species the original function has ceased, would require impossible study. While it is plain that a hundred needs may each be represented in the pattern- and colour-schemes of animals, it is also plain to an artist’s eye that in most butterflies all visible details of colour, pattern, and form are essential parts of the representation of flower-scenery. And it is surely conceivable that, in a certain region, one particular form of flower-scenery-representation may furnish such advantages to butterflies as to cause many widely-separated species to become modified till they wear a common aspect; and it is conceivable also that there would be one common form of wing which would best lend itself to this scheme. Surely we do not know enough of the habits of these insects or of the regions that may be their strongholds to 558 Mr. A. H. Thayer on feel sure that this hypothesis is absurd; and were it correct, it would complete a chain of seemingly perfect evidence. After we see how inexplicable it would be if butterflies did not either resemble flowers, or represent some portion of flower-scenery, why should we, in view of the endless variety of flower-forms, stick at any form or pattern in the butterfly that frequents them ? One must constantly remember that any pattern is less conspicuous than bright, unshiny monochrome. Therefore, “conspicuous” is not the right word for the character of patterned butterflies. Now since the Jthomiinew, Heliconine, and Danaine, such for instance as the similarly coloured cow-red and chrome-yellow, black-bordered Melinxwa, Heliconius, and Lycorea (and equally, in other colour-schemes, all the other so-called mimicking groups), are in every way com- pletely painted by Nature into these three tones,—the note of shadow under vegetation making their borders, which it occupies, coalesce with the shadow under the flowers, and disappear, while the red and chrome wonder- fully reproduce the colours and patterns of such flowers as Odontoglossum triumphans, who shall say that it is not to this flower—which perhaps, by its abundance, dominates the region—that these cow-red and chrome-yellow butter- flies owe their common appearance? Some such flower may be overwhelmingly attractive for its honey. Perhaps the most conclusive of all our evidence is to be seen in the transparent winged members of these mimicry groups. Dismorphia orise, for instance, with its green transparencies enclosed in a pattern of the same velvety dark fuscous that I have already described. What conceivable artifice could offer greater opportunity for frequently remaining unnoticed amidst flowers and leaves ? These little green windows must of course allow any bright object to show through them, while the fuscous cuts the aspect to pieces by representing a shadow far below the insect. The very word transparent wrecks any theory of conspicuousness or adaptation suitable for a badge. Add to this the present belief that the trans- parency has been attained through selection, and ought not those who hold this theory to believe that concealment was obviously the goal of a change toward invisibility ? It is hard to conceive of a better device for representing little green leaves than by these glossy green, leaf-shaped, Protective Coloration in its relation to Mimicry, ete. 559 and leaf-veined windows, bordered with imitation back- ground, and ever ready to look like glossy leaves the moment they are extended over a bright flower or other bright object. Professor Poulton has already noticed the efficacy of the imitation hole in the wing of Gvapta (a device similar in effect to the gold dots on some pupe). During the writing of this article I have been learning that iridescence itself is an immense factor of conceal- ment, far greater than I at first realized. I have lately had excellent opportunity to study several species of golden-brown butterflies with sheeny black tips spotted with white, and I begin to realize the wonderful power of this combination. The white dots stand changeless, while upon the black, in bright sunlight, faint rainbow sequences dissolve the actually flat wing-surface into liquid depths, apparently wholly detached both from the insect and from the white spots, which appear, as I before said, to be shiny points like dewdrops down in the spaces below the buttertly. If butterflies were mimicking each other, Mr. Blandford’s objection (Proceedings of the Entomological Society, 1897) that the resemblances would be hypertelic would seem true. Since an attempt on Nature’s part to give common colours and patterns to a group of insects involves no need that any one of them shall have sharp delicate contours of spots, or have subtle gradations, these species would, if their object were to resemble each other in their colour and markings, stop short of such sharp contours, ete. On the other hand, if they are representing flowers or any organic forms instead of merely patterns, etc., on forms, they would profit by the utmost minute finish of every part of their design, since just this finish, this microscopic- ally perfect smoothness and minuteness of detail is an essential characteristic of flowers and even of leaves. Upon my hypothesis, the many “ warning-colour’ species that have dull-contoured spots instead of sharp ones, would seem (as they do to the supporters of Mimicry) to be species in process of adaptation, but to the aspect of Jlowers, instead of to that of each other. As soon as the advocate of the Mimicry theories sees that to wear the region’s prevailing pattern tends to coi- ceal, his case looks bad; since we see throughout the animal kingdom common coloration, and often common 2) 560 Mr. A. H. Thayer on form in widely separated orders, plainly accompanying common environment and habits. The Salmon’s silver, grading upward into dusky, and downward to purest white, is identical with that of countless fish in many groups, and no one doubts that environment and habits are the cause. Among birds, Emberiza miliaria, Anthus pratensis, Alauda arvensis, and Alauda arborea are four species of three genera for all four of which one minutest colour-and-pattern-description would almost suffice; and the same colour-scheme and pattern with slight varia- tions is found on a great many other species throughout the world, both of Passeres and even Scolopacide and Galline, telling plainly of life on the ground amidst grasses. Among the Scolopacidxe, many females and young of the Anatide, and the Laridx, Nature betrays, in the main, great lack of variety in design, easily accounted for by the lack of variety in the aspect of the environment. In a broad survey of the animal kingdom we perceive that everywhere the degree of colour-and-pattern difference between different members of an order, family, or genus keeps pace with the degree of variation in their environ- ment’s aspect. Why may not the circumstances of a group of butterflies furnish them similar needs to wear a common livery, even if we cannot see the reason? Might they not tend also to have their flavour similarly affected by similar food ? The Spruce Grouse (Canachites canadensis) is saturated with spruce flavour, and the world is full of such cases. Even the amazing similarity between members of these groups is no proof they may not, for reasons which we have not discovered, profit each by exactly the same form of concealing-coloration. It should be borne in mind that it is not a flower that these mimics evidently represent, but a certain combination of the flower’s aspect with that of its surroundings. Hence there may be one best way to render this. Butterflies on wing are conspicuous, but are wonderfully protected by their jerky flight, which is completed by their wings being so large as necessarily to throw the body up and down at every movement. This latter advantage, attainable by no other conceivable means, may be a great factor in the whole matter. In flight they are doubtless practically safe, 7. ¢. too trouble- some a quarry to be seriously decimated. I send, for Professor Poulton to exhibit, photographs of a number Protective Coloration in its relation to Mimicry, etc. 561 of so-called conspicuous butterflies (dead specimens), the examples having been placed as far as possible without an unfair attempt to favour my argument, except in a few cases where the attempt is obvious. Surely they speak eloquently. Could they be seen in their colour- coalition, they would speak even more so. Any one care- fully examining them will see that, in most cases, their dark parts are not distinguishable from the background (although the average person, unaccustomed to analyze his sight, will, by recognizing the butterfly through its pattern, Jancy he sees every part). The very keynote of the zoologist’s error is psycho- logical. One sees only what is out of place ;—that which is in place is harmonious and unnoticed. We know how many of these concealed animals we sce, but we do not dream of how many we pass by. By tracing back to so palpable an example as our Sphinx-moth photograph, we see that the various com- binations of sharp-edged markings with delicate blendings, exactly resembling the combination of patterns made by any sharp-edged fabric lying near a ground on which its shadow falls, do represent such combinations of form ; so that we must believe that so elaborate and delicately complete a design would scarcely exist merely to identify a species as unpalatable. We find on several Preces, as on many Vanesse, and Papiliones, very highly developed cases of the varied combinations of design worn by multi- tudes of the most obviously protected birds, and other animals ;—slight variations of representation either of near objects casting a shadow on the background, as in the cats, snakes, and moths. mentioned, or of near objects relieved against more distant, fainter ones, as in the European Woodcock’s wings, many female Pheasants, and male Pheasants’ tails, such as that of the Copper Pheasant. Doubtless each species has some particular headquarters, as it were,—some region which it fits best,— and unless we chance to study it in this very region, and at the most favourable season, we shall never witness the full operation of its protective colour-scheme. Mr, Frank M. Chapman has already pointed this out in a_ paper entitled “On the Birds of the island of Trinidad,” published Feb. 1894, in the “ Bulletin of the American Museum of Natural History,” a paper containing some very prophetic glances into the future of protective coloration. * 562 Mr. A. H. Thayer on Apparently Nature has two main _protective-colour schemes; one of which is closely imitative of the very near environment of the animal, and applicable to such species as sit close, and keep still, for concealment, as do the tree- toads, moths, goatsuckers, certain snakes, and, among butter- flies, the species of Grapta. (The latter, at least, keep very still when resting, and expose at such times only the rock or bark representation on the under-side of their wings.) Among those butterflies, on the other hand, which have no pronounced habit of protecting themselves in this manner, Nature seems to have been forced to a bolder, more positive way by furnishing them an upperside bearing a sort of conventionalized representation of the predominant details among which they are destined to move. Flowers, of course, must almost always be present. And always the notes of the conventionalization are perfect. Here is a most impressive argument, viz., so-called con- spicuous butterflies have the body, head and all, exquisitely effacively graded. Would it not be absurd for Nature to spend energy in effacing the body while making the wings conspicuous? The multitude of species, the world over, whose main colour is largely the peculiar fuscous of shadow under vegetation, have in most cases not merely this shadow-colour, which so perfectly coalesces with the shadow and apparently vanishes from the insect, but also a system of exquisitely delicate perspectives within the patches of shadow-colour; as in the genus Caligo es- pecially. I mean that Caligo is an exquisitely developed representation of the perspectives which an artist sees in peering down through the openings between the flowers. The parts of the world which I know well do not yet furnish me a clear vision why so many butterflies, such as several Preces, and Anosia plexippus, for instance, have these delicate perspectives done in golden brown instead of either shadow-colour or the more delicate flower-colour ; but that this delicate design does represent perspective, and would be wasted if used for any attempt at conspicu- ousness, and that it is entirely akin to the perspectives rendered on perfect shadow-colour in so vast a number of species, is reason enough for trusting it to prove to be some form of concealment device; and on red flowers these species show surprisingly little. I myself suspect that butterflies of the A. plexippus type represent half a concave flower. Watch any butterfly of this class, or any Protective Coloration in its relation to Mimiery, ete. 563 of the classes in which the pattern, when the wings are open, arranges itself in amphitheatre-like semicircles of stripes or dots, etc. When such a butterfly rests with open wings on a flower, its head is at the centre, its antennze form two stamens, and these semicircles seem to belong to half the flower of which its head is the centre. In several Preces, and many other butterflies, there is a general representation of something like a bunch of stamens casting their shadow deep under them in the flower’s cavity. Usually a butterfly’s upper-side has the exact colour-note characteristic of flowers and _ flower- scenery seen from right overhead (take, for example, Papilio turnus); while its under-side is a picture of such greater distance as would be seen from the side position necessary for beholding it when the wings are in their characteristic vertically-folded position; and this is the position from which enemies on neighbouring bushes would see it. So-called “conspicuous” butterflies have, in short, their upper-side designed with the full strength “values” of the nearest flowers looked into from above, and their under surfaces designed in notes more delicate, to counterfeit the distance, and a perfectly effacively- graded body. Their under-side is also more delicately finished, as if against the nearer inspection possible from neighbouring bushes. In fact, they wear every conceivable aspect to fit them into the background from each point of view, and make you think you see through them; or else, seen from above, to make you think, as in the case of the Pierine, that you see a flower itself. How can such a case call for a theory that is based on the hypothesis that they are conspicuous? One very important fact is that we have abundant proof that animals, including birds, have totally different sight from ours; and the existence of these patterns, etc., unless it can be denied that they even tend to efface, should be taken as proof that they sufficiently succeed in effacing. Otherwise, why are they there, when almost the whole animal kingdom does need concealment? A fox, a deer, a bear, a grouse, a turkey, or any small bird or mammal, may come almost to one’s feet if one stay still, yet flee wildly on seeing any motion. Is not this sufficient proof that even if we were usually able to detect a Papilio when it is effacively situated, it is no sign that a bird could do so, if the insect kept its place ? 564 Mr. A. H. Thayer on Butterflies very often remain unobserved amidst flowers or other vegetation, by any one approaching (especially if he be not keenly in search of them) until once flushed. Of course our yellow and our white Perinx are pretty sure to catch the eye of the person approaching, if, as very commonly, they are found amidst dark vegetation. Yet their colours are precisely those of our most abundant flowers, just as they are our most abundant butterflies. This fact harmonizes with my argument that, however conspicuous in many situations, few animals are so in the place or region to which they doubtless owe their abund- ance. We see largely the overflow individuals from a concealing region into a less favouring one, and erroneously think of the species as typical of the region where it is visible to us. The gentle waving of the wings, so common among butterflies when they are feeding, seems plainly a protective imitation of the swaying of leaves and flowers in the breeze. Any one who has photographed outdoor vegetation knows how seldom it stands still. To sum up, the general aspect of each animal’s environ- ment, throughout the animal kingdom, is found painted upon his coat,in such a way as to minimize his visibility, by making the beholder think he sees through him. How has it chanced that, while this fact has long been recog- nized, in a crude way, in many fields of zoology, it has remained essentially unnoticed in butterflies? Their most critical moments being passed upon flowers, the aspect of flowers combined in various proportions with the dark vistas down among them to the shadowy earth beneath, is exquisitely painted upon a vast majority of the world’s butterflies, and on none more plainly than on those called conspicuous. The Pierine are mainly representations of flowers, though surrounded by a dark border which appears to belong to the shadows beneath it. On the other hand, there are a vast number of dark species which represent a portion of this shadow-under- vegetation, with bits of yellow vegetation, or of flowers, seen against it (these of course being rendered by the light markings). Could small, bright patterns on dark possibly be more perfect generalizations of small blossoms, buds, and stems ? I cite the following examples of the various colorations described. Among the Brassoline, Caligo eurylochus is a marvel of Protective Coloration in its relation to Mimiecry, ete. 565 wholly effacive design, so subtle as to make it absurd to suppose that Nature could be trying to have him conspicu- ous, or to use such delicate gradations for identification. Caligo telamonius and Caligo demosthenes are even more wonderful examples. Cynthia has a wonderful multiplicity of perspectives represented on its surface. Black and green Nymphaline are notably orchid-like in design. Their dark tips disappear, uniting with the shadows. Dione has good near-scenery on its upper-side, while the silver spots of its under-side appear in a side view to cut holes through its wings. The Danaine butterfly Zimnas chrysippus is covered with design which I am not prepared to interpret. Whether or not it is a flower, the four interior spots on the upper-side of the hind-wings may pass for stamens, as may also, of course, the antenne ; and whether or not the yellow-red ground counterfeits the colour of a flower, it represents a flower’s form. Caduga melancus has the colour- scheme of the skunk, with, of course, similar advantages. The Satyrinew, i.e. the dark ones, with strong, light patterns, have also the sknnk’s colour-principle. The Danaine, Ithomiine, and Heliconine of South America, Lycorea, Melinxa, and Heliconius, for instance, display marvellous mutual resemblance, yet their likeness to Odontoglossum triumphans, when their dark tips are cut out by coalescing with the shadow, is most impressive. Among the transparent Satyrinw I may mention Pierella nereis. Unmistakably the whole surface of this insect (and likewise that of Citharias menander) pictures a single flower. Piecrella astyoche represents flower-scenery (likewise Prerella rhea). In the Oriental Danaine genus Huploea we see exquisite shadow-perspective over which white spots relieve. The blue sheen, seldom or never occurring on both wings at once, additionally effaces, In the Lycenide the exquisite blue species represent flower-cups, their black border of course detaching into the background. The above examples I have chosen from all the families I have lately examined, which do not include the Skippers, or the great mass of Papilionide. Let me add a few more reflections, all harmonious with my theory. 566 Mr. A. H. Thayer on The act of flight tends to obliterate pattern, by the too quick substitution of one colour for another before the eye. A black-and-white butterfly, therefore, tends to look simply grey in flight. It is not necessary to conceive that a bird must find the imitation flower on its proper plant, if the flower represent a type common in the neighbourhood. 37s) antenne are broken. Taken at ‘ Little Chelsea’ in July last. —Mr. Westwood. It is probably exotic, having been found in a cup of coffee.” “The British species” (of the family Bosrricnip™) ‘are few in number, of small size, and considerable rarity ; indeed it is not improbable that some of them are not really in- digenous, but have been imported in timber, ete., from abroad, as in the instance of Dinoderus ocellaris, described by Mv. Stephens, from my collection, which I found floating in a cup of coffee.”— Westwood, Int. Mod. Classif. Insects, L., p- 278 (1839). Professor E. B. Pouuron, F.R.S., read the following note on “Heliotropism in Pararge and Pyrameis,” communicated by Dr. G. B. Lonesrarr, M.D.:—“Following up my observa- tions on the attitude at rest of Pararge schakra, Koll., made near Simla in October 1903,* I paid a good deal of attention in February and March of the present year to P. meone, Cram., a butterfly that I found in varying numbers in all the parts of Algeria that I visited. This is either a southern form of P. egeria, L., or a closely allied species in which the yellowish spots are replaced by fulvous. ‘It is fond of settling on sandy roads, rocks, walls, or the leaves of trees or shrubs, compara- tively rarely visiting flowers. It first pitches, invariably if might say, with its wings about three-quarters expanded, and in the vast majority of cases with its back to the sun, the axis of the body being rarely more than 45° to either side; im- mediately after settling it more often than not adjusts itself, by a quick movement, so as to make its tail point fairly accurately tothesun. After thisadjustment, if at all, it closes its wings over its back, and as a necessary result its shadow is reduced to, or approximates to, a mere line. There can, I think, be no doubt that this habit is a great protection to the insect, since when resting on fairly flat surfaces the shadow of a Satyrine or Nymphaline butterfly with cryptic under-side is often more conspicuous than the fly itself. “‘T quote two cases from my notes :— ‘Feb. 8, Guyotville. Watched a specimen settle about twenty times. The wings were alwaysat first expanded about * See Trans. Ent. Soc. Lond., 1905, p. 67 and 136. ( He) [xxix three-fourths, an adjustment of its position was in most cases made immediately, and after that the wings were raised over the back. In about twelve cases the orientation was perfect and the shadow a minimum ; in seven or eight cases the orien- tation was imperfect, with a maximum error of about 45°, but usually much less. “Feb. 25, Biskra. Watched one settle three or four times, always with a shadow near the minimum. “Only one specimen of P. meone was ever seen to settle facing the sun ; it did so three times, a fourth time turning its tail in the usual way. This was at Biskra on March 5th, and I noted at the time that the sun was not shining strongly. Two only were observed to settle with the axis of the body at right angles to the sun. One of these appeared to be crippled in the legs, since it alone always sat on one side. ) [Ixxiv, lxxv was dull and cloudy, and the insect was resting in a semi- torpid state among the flowers of the white dead-nettle (Lamium album) in a hedge. A week later, on May 13th, between 4 and 5p.m., when searching the same hedgerow, another individual was found in an almost identical position. Hanging in the midst of the largish white flowers of the Labiate the butterflies were beautifully concealed, and were indeed only found because the plants were carefully examined for other insects. “On August 17th, between 7 and 8 p.m., when looking for larvee on the hedge bordering my garden, near the Cowley Road, I found two rapx within a few inches of each other. Both were resting on the silvery under-sides of bramble leaves. In both cases, however, the leaves were twisted and the lower surface had become the upper. Again, on August 20th, in a lane leading to Temple Cowley, at 5.30 p.m., I watched an individual flying slowly along a hedgerow, every now and then resting for a few seconds. Finally, after many attempts, it settled down, apparently for the night, and on going to look more closely, I found that it also had chosen the under-side of a bramble leaf. Although not quite so well concealed as among the white flowers, these last examples blended wonderfully well with their environment. “‘ After some years of close observation of the resting habits of insects in general, I feel convinced that they possess an inherent tendency to select an environment that aids in con- cealment ; and as the various species differ in appearance so do they select diversified situations suited in each case to the particular requirement of the insect.” A discussion followed, Mr. H. J. Etwes expressing his conviction that the use of surroundings by insects, and Lepi- doptera especially, for protective purposes simply, was still an open question. Colonel J. W. Yersury mentioned the case of Luchloé euphenoides and Zegris eupheme roosting at Granada on plants of Biscutella, the appearance of the insects at rest closely approximating to that of the flower heads. Mr. H. Row.anp-Brown observed that he had noted a similar resemblance between a specimen of Pieris napi and the flower of Leucojwm on which it rested for the night. Mr. G. C. lxxv, lxxvi] ( Hs) CuamMpPion said that he had noticed specimens of Gonepteryx rhamni seek the under-sides of bramble leaves. Dr. T. A. CHapman said that Col. Yerbury’s observation on Euchloé euphenoides resting on the flowers of Biscutella is one that may be often made in the South of France, and few English Entomologists have not observed 7. cardamines at rest on Alliaria flowers, or on some Umbellifer that roughly resembles it. These facts seem to give the clue to how the practice of these Crucifer-feeding Pierids of affecting objects of their own colour for resting arose. In so many of these cases, the food-plant is in flower when the butterfly is on the wing, and in the case of Huchloé the flower head is the place selected for egg-laying. It comes about, then, that the butterflies frequent the flowers of their food-plant, both for the honey they afford and for egg-laying. That it would often happen, therefore, to be the resting-place of the butterfly when overtaken by a sudden failure of sunshine is obvious. Nothing further is needed as a basis for natural selection to gradually accumulate in association, the characters of resting on the flower of the food-plant, and assimilation to it in colour. A butterfly, searching for a flower head to rest on, will act of course in the same way as one searching for it for any other _ purpose, viz., it will discover at a distance an object of the desired colour, and will be able to verify what it really is, only after a close approach. If it wants to suck honey, or to lay an egg, such verification is imperative, and all collectors are familiar with butterflies closely approaching a piece of coloured paper, a dead leaf or other object, and only when quite close discovering that it is not the desired mate, or flower, and at once departing. But if a resting-place for the night is desired, such verification is not absolutely essential, and a place must be chosen, so that if after several tries a near approach only produces disappointment, an occasion at length occurs, when advancing evening makes it necessary to appropriate the resting-place without the final verification. Thus a Pieris or a Luchloé will learn to accept as a resting- place any white object, even if it be not a flower head of a Crucifer. But if it be objected that cabbage and turnip, the usual ae [Ixxvi foods of our ‘‘eabbage” butterflies, have yellow flowers, the reply is that these foods, for these butterflies, are entirely human inventions, and therefore comparatively modern. Their natural foods have chiefly white flowers, such as, Nasturtium, Avrabis, Draba, Cochlearia, Thlaspi, Lepidium, Turritis, Alliaria, and many others, the two last mentioned being the favourite foods of HZ. cardamines. It may also be suggested that the frequently very yellow under-sides of our common ‘‘cabbages” are due to the yellow flowers of our cultivated Brassicas, and of such wild Crucifers as Raphanus sinapis, and Barbarea. The Presipent, Mr. A. J. Cuirry, Dr. F. A. Dixry, Pro- fessor E. B. Poutton, and other Fellows offered observations on the subject. : nas EXTRACTS FROM THE PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF LONDON (Fepruary 7TH—Marcu 21st, 1906). —<———— Wednesday, February 7th, 1906. Dr. F A. Drxry exhibited specimens of South African butterflies captured by himself and Dr. Longstaif, and re- marked upon them as follows :— “It may be remembered that at a recent meeting of the “Society (Proc. Ent. Soc. Lond., 1905, pp. liv—lix), I gave some account of the scents observed by us in South African Pierines, calling attention to the fact that they were practically without exception of an agreeable character and confined to the male sex. On the present occasion I wish to speak of the perfumes detected by us in butterflies belonging to other groups ; some of these odours having a similar character to those of the Pierines, while others belong to a different category. “ Mycalesis safitza, Hew. ¢. On separating the fore- and hind-wings, so as to expose the well-known ‘tufts,’ I at once perceived a strong odour of chocolate, perhaps combined with a trace of vanilla. This I noted at the time as ‘one of the strongest butterfly scents known to me.’ I found no odour in the female. Dr. Longstaff also detected a ‘ chocolate scent, not strong,’ in the tufts of the male. “Two males of Mycalesis perspicua, Trim., examined by Dr. Longstaif, emitted a ‘very strong treacly odour—quite distinct from the scent of M. sajfitza.’ To my perception the scent was rather of the chrysippus order, with a suggestion of burnt sugar or treacle. We had no opportunity of testing the female. “Two male specimens of Yphthima ctonia, Hew., and three of Pseudonympha cassius were tested by me with a negative result. (a2 [ii, iti “The males of Byblia goetzius, Herbst, yielded a very distinct and agreeable odour of sweet chocolate, mingled, as in Mycalesis safitza, with a suggestion of vanilla. Dr. Longstaff reports a chocolate scent in the only specimen examined by him—a female. ‘‘T found a similar chocolate scent in a specimen of Gegenes oculata, Trim. 3. Gegenes zetterstedti, Wallgrn. 9, was odourless, as also was a specimen (not yet determined) of Pterygospidea flesus, Fabr. “ Planema ayanice, Hew., has been stated by Mr. Marshall (Trans. Ent. Soe. Lond., 1902, p. 413) to have no smell. The green juice exuded from a male specimen appeared to me to have an odour like that of a crushed cabbage leaf, which was by no means unpleasant. “ Both sexes of Acraa alboradiata, Auriv., have a distinct odour which is described by Dr. Longstaff as ‘musty’ and ‘like old hay.’ The female was independently noted by me as smelling like musty straw. “The scent of Acrxa anemosa, Hew., seems to vary greatly in strength in different individuals. One of the males tested by me had no apparent odour, Another male and a female both smelt strongly of damp, fusty straw. Dr. Longstaff’s specimens, all males, gave a ‘ musty’ odour of varying intensity. Mr. Marshall (oc. cit.) states that A. anemosa ‘emits a very strong smell when pinched, being the only Acrzwa in which I have noticed this, though possibly acara does the same,’ “No odour was perceptible in the wings or crushed thorax of Acrxa cahira, Hopft. ¢. Mr. Marshall (cb¢d.) reports that he was unable to detect any trace of bitterness or acridity in this species. “Dr. Longstaff found a slight snuffy scent in the male of Acrxa encedon, Linn., and an evanescent disagreeable odour, not very strong, inthe female when crushed. The yellow juice of this species is said by Mr. Marshall to be slightly bitter, but not very markedly so. “ Acrea doubledayi, Guér. ¢, emits a yellow juice which on one occasion seemed to me to be scentless. In another male I detected a slight fusty odour. Dr, Longstaff reports an ‘old hay’ scent on crushing, in both male and female. iii, iv] Ca ey “ Both sexes of Acrea atolmis, Westw., were found by Dr. Longstaff to possess a faint odour, which, however, he does not describe. I did not examine the female, but a male specimen appeared to me to be scentless. “The smell of musty straw was very distinct in a female specimen of Acrea caldarena, Hew. It was only slightly apparent in a male examined by Dr. Longstaff. “In Acrea atergatis, Westw., [ found that the same musty odour was accompanied by a strong ammoniacal scent, like that of stable-litter. “Both sexes of Amauris echeria, Boisd. (form albimaculata, Butl.), yielded a similar smell of musty straw, accompanied in this case by an evanescent sharp or pungent scent like that of vinegar. A considerable amount of yellow juice, which seemed to be tasteless, was exuded by one male specimen. The characteristic smell adhered to the fingers after crushing a female specimen, though in this instance no fluid was seen. In regard to A. echeria, Mr. Marshall remarks that in the few specimens that he tried, no juice was emitted ; but they had a nauseous taste and a strong smell which reminded him some- what of that emitted by many Coccinellidx. Dr. Longstaff observed the musty smell and the transient pungent odour in both sexes ; the latter he compares to acetylene. One female was noted by him as possessing ‘a disagreeable odour like some animal.’ “The scent in both sexes of Limnas chrysippus, Linn., in- variably appeared to me to be of astrong and disagreeable nature, like that of cockroaches, often stronger in the female. The odour of the male seemed to contain an additional con- stituent, which I am inclined to compare to the perfume of burnt almonds. I found no increase of the scent when the glands of the hind-wing were crushed with the forceps. Dr. Longstaff noted a disagreeable odour in both sexes—stronger in the female—which he likens to that of musk-rats or cock- roaches. The excised glands of the male yielded on pressure a yellow or brown juice, without perceptible taste or odour. (For his impressions of LZ. chrysippus in India see Trans. Ent. Soc. Lond., 1905, pp. 87, 89,108,137.) That great individual differences exist in the appreciation of these scents appears * (J [iv, v from Mr. Marshall’s statement that in his experience ZL. chrysippus emits no smell. “A specimen of Charaxes varanes, Cram. ¢, on being squeezed, emitted an odourless yellow juice. Another was noted by Dr. Longstaff as having a ‘treacly’ odour. A female was thought by him to havea smell likecowdung. To me the scent of the same specimen recalled that of L. chrysippus. “ Salamis anacardii, Linn., has an animal-like scent which to Dr. Longstaff suggests the odour of rabbit-hutches. It appears to be stronger in the female. This may be compared with Wood-Mason’s statement that the females of Papilio dasarada, Moore, ‘had the strong scent of caged porcupines with a touch of musk’ (Journ. Asiat. Soc. Bengal, 1886, Vol. LV, Part II, No. 4, p. 374). ‘*Three specimens of Weptis agatha, Cram., captured by me in Natal, emitted a strong and very disagreeable scent, much like that of Z. chrysippus, but more intense. ‘Two specimens from the Zambesi, however, are reported by Dr. Longstaff as having a ‘slight sweet scent,’ and ‘? slight ‘scent’ respect- ively. The Natal and Zambesi forms of this species certainly differ in aspect, and it may be that a corresponding difference exists in their scent-producing capacity. All five specimens seem to be males. “T found no smell in Neptis marpessa, Hopff. ¢. ‘““A male specimen of Hypolimnas misippus, Linn., had a smell like coffee; not very strong. “The male of Hamanumida dxdalus, Fabr., was found by me to smell like burnt sugar, or caramel toffee. A similar scent of burnt treacle, accompanied by a ‘fairly strong animal scent,’ was noted in another male specimen by Dr. Longstaff. In two others, when dead, he detected a ‘mousy’ odour. **T could find no scent in Lurytela hiarbas, Drury, g. Dr. Longstaft records of two specimens (sex undetermined) ‘? snuffy scent.’ “ Precis clelia, Cram. ¢, is said by Dr. Longstaff to have a treacly scent. ‘The smell of fusty packing-straw, so common among the Acrzas, is also found in Papilio demodocus, Esp. It is some- times combined with a smell that suggests cabbage-water, or a v, vi] So) Na) kitchen sink, and was found by Dr. Longstaff to be stronger in the female than in the male. “‘ Papilio cenea, Stoll, ¢, has a similar odour ; less ‘ musty,’ according to Dr. Longstaff, than that of P. demodocus. “ Papilio lyeus, Doubl. 6, is occasionally scentless. Imms) Esom M. Jacoby, Esq., F.E.S.; Frank Leney, Esq. ; Dr. G. B. Long- staff; Guy A. K. Marshall, Esq., F.E.S. (two memoirs) ; Pro- fessor’ 1... ‘C.. Miall, F.R:S., and, R. Shelford, Bsq:s Dr. 49 Minot, Hen. D.Sc.; W.T. Pearce, Esq.; Dr. A. Petrunkewitsch and Dr. G. V. Guaita; William Prest, Esq.; G.A. J. Rothney, Esq., F.E.S. (together with a memoir by Peter Cameron, Esq.) ; Baron C. R. Osten Sacken; Monsieur Henri de Saussure, of Geneva; O. A. Sayce, Esq. (two memoirs) ; E. H. J. Schuster, Bsqas Dt. We och; Aj E,ohnipley, sq... MA, Christ:s' Col- lege, Cambridge (two memoirs, one in conjunction with Edwin Wilson, Esq.); Miss Caroline G. Soule; R. South, Esq.,F.E.S. ; Mark L. Sykes, Esq. (two memoirs); Abbott H. Thayer, Esq. (two memoirs); F. V. Theobald, Esq.; Roland Trimen, Esq., Monee HoR.o. Wr A. Voeltzken; Dr €. He Vocler: the Rev. Father Wasmann (two memoirs) ; C. O. Waterhouse, Esq., F.E.S.; G. A. Waterhouse, Esq. (two memoirs) ; Pro- fessor W. M. Wheeler (two memoirs); J. J. Wilkinson, Esq. The following publications of the year 1903 were purchased for the Department :—The parts of Barrett’s “ British Lepi- doptera,” the Ray Society volume, the volume of the Zoolo- gical Record, the numbers of the “ Entomologist’s Monthly Magazine,” the “ Entomologist,’ and the “ Entomologist’s Record.” FE. B; POULEON: D piesa tl es ers | ie - cone Mowe oe a} a SS aa eae oe a vical apie : 7 eae) ey ae ete hae, anes ‘=ecn a ‘ Re tes > NY oe eT REO er ee, ee . . | ae 1G Pr np 0 1 eS eles Se te = 7 ae, { Ps ikke Weis 4 “hie yt} Pete nn .8 i A AT). ¢e Saas : ie Po deyitias oor et .aee _ z= yal enter ty POE fea Fe i Mareen = -. gene Ti ae Vi gelirtc Ard “ak ieee Teel i ‘i OU Bee ewes Wiexbeah sud! dwerceY micoare ; y Diet eT ae 5 Pi Cos @8 (Pt dea om eee ST Ail eee, si ow rh ai a id " th) is Can ’ > os oo Te ele ed ee ealtle hag siStin “a kaw ae > eel vee Yd eet et ee J ree |v ins yi Clo DES Wi Atle ew . A : re ee SU eae ie . eA be ml ts elo | (es eee ies can ae ‘ m : 4 Or eee Sf - Report of the Hope Professor of Zoology, 1904. Summary of the chief accessions acknowledged in the Report for 1904. Among the additions to the British Collections one of the most interesting has been an important Asilid fly new to the British list, captured by Mr. W. Holland at Stow Wood (June 10, 1895) and Tubney (June 2, 1901). Last year Mr. Holland’s discovery of a striking beetle (Gyxandrophthalma affinis) new to Britain, from Wychwood, was mentioned in the Report of the Hope Department. Now it is followed up by this interesting accession to the list of Diptera :—NVcottamus cothurnatus. The three specimens have been determined by Mr. G. H. Verrall, and were exhibited by him at the Entomo- logical Society (Proc. Ent. Soc. Lond., 1904, p. xxxiii). For many years the generosity of Mr. Horace Donisthorpe has been acknowledged in these Reports. During the past year he has again presented valuable additions to the British Collections, especially the beetles. Up to the present time we owe representatives of over 970 British species of this Order to his kind help. Although properly belonging to the present year, it is impossible not to allude to the splendid collection of nearly 7,000 British Micro-Lepidoptera recently presented to the University by Mrs. E. C. Bazett, of Reading. These minute and excessively delicate specimens are most difficult to obtain in good condition, and even more difficult to “set.” The existing British Collection of Micro-Lepidoptera—in part Westwood, in part Spilsbury, and in part the old Oxford Entomological Society—is by no means satisfactory ; so that Mrs. Bazett’s generous gift of the collection to which she has devoted many years of labour, will enable us to replace thou- sands of poor specimens without data by beautiful examples accompanied by excellent records. It is hoped that a full and complete account will be furnished in the Report of the present year, but an immiense amount of work will be required in B 2 “staging” the specimens, printing, labelling, and arranging. How great this is likely to be may be to some extent inferred from the number of the specimens. Among the African accessions a deep and special interest belongs to the specimens of that remarkable mimetic “ Swallow- tail” — Papilio dardanus form cenea, bred and presented by Mr. G. F. Leigh, of Durban. As long ago as 1870 Mr. Roland Trimen, F.R.S., F.E.S., brought convincing evidence that a butterfly, of which the male had been described as one species and the different forms of the female as three other species, was in reality but a single species with a non-mimetic male and three forms of mimetic females, each resembling a different model. Professor Westwood, who himself described one of these females as Papilio trophonius, at first doubted the inter- pretation, but he was ultimately convinced, and the present Professor well remembers the delight of the great naturalist when he showed and explained the fine series of forms of the female in the Hope Museum, all bred from the larvae found in the same garden in King William’s Town, South Africa, by Mr. J. W. Mansel Weale. But the conclusive test of breeding from a single pair of parents had never been applied until Mr. Leigh undertook the work at Durban in 1902 and 1903. The commonest form of female of this species in Natal (cexea) may be called A, the rare form (Aippocoonoides) B, the rarest form (trophonius) C. Mr. Leigh captured (Sept. 18, 1902) a male 2 coztw with form A. From the eggs he succeeded in rearing 18 males, 24 A-females, and 3 B-females. A year later he captured form C, and from its eggs reared 3 males and 2 A-females. Finally, during the past year Mr. Leigh watched the oviposition of form C. He failed to catch the parent, but collected the eggs and bred from them 6 males, 5 A-females, and 1 C-female. The two earlier breeding experiments are described in Trans. Ent. Soc. Lond., 1904, pp. 677-91, Plate XXXI. Further details will be found in the later part of this Report; but this final conclusive justification of Mr. Trimen’s inferences of over thirty years back, is of such great importance and interest that it has been thought well 3 to summarize the results of the work in this section of the Report. At the time when the above paragraphs were written it was intended to summarize the whole of the chief accessions in this part of the Report. The necessities of space have, how- ever, prevented the fulfilment of this intention. A full account of the numerous and valuable donations received by the Department will be found towards the end of the Report. The Rothney Collection of Hymenoptera. In this place it is appropriate to speak of the splendid collec- tion of Oriental Hymenoptera, containing large numbers of types, bequeathed to the Department by Mr. G. A. James Rothney, F.E.S., together with his fine British Collection of the same Order, the manuscript notebooks relating to the collections, and the parts of his library dealing with this group of insects. In addition to the Hymenoptera, Mr. Rothney has _ be- queathed a very complete collection of the butterflies and dragon-flies of Barrackpore Park. The names of the butter- flies have been published by Dr. Frederick Moore (Zztom. Mag., July, 1882). All the books, cabinets, and boxes have been carefully labelled “ Bequeathed to the Hope Department,” and Mr. Rothney has made arrangements for the whole to be conveyed in a spring van by road to Oxford without any expense to the University. This generous benefactor has already sent to the Department bound volumes of the Transactions of the Entomological Society of London, being a complete set from 1872 to 1903, both years inclusive. These Transactions are more greatly needed than any other single set of volumes in the Hope Library, so that a second series will be of great value, especially when the Department spreads in a few years into the Southern Section of the old Radcliffe Library. When the Rothney Collection of Hymenoptera is added to the Collections of W. W. Saunders, Sir Sidney Saunders, F. W. B 2 4 Hope, J. O. Westwood, to the numerous types of Frederick Smith, and to the large number of accessions registered in these Reports during the past ten years, the most interesting of all the Orders of Insects will be represented in Oxford by one of the great collections of the world. Financial gifts and grants to the Department. Much kind assistance has been rendered in the difficulty of meeting the various necessary expenses of an active and rapidly growing Department. It had been hoped that the University would be able to provide an additional £100 to the annual grant, which has only been increased by £10 since the year in which the present Professor was appointed (1893). But the state of the University finances made it impossible to expect this sum in 1904, and £50 was voted. Dr. Longstaff also made a generous contribution of £50, and a kind promise of £20 made by the late Warden of Merton a few months before his death was generously fulfilled by his executors. Dr. Longstaff, during his visits to the Department, was im- pressed by the congestion due to the continual inflow of material and the very insufficient means of dealing with it. He generously offered to provide another Assistant during 1905 and 1906, an offer gratefully accepted by the University on Feb. 7, 1905. Mr. J. Collins, of Warrington, has been ap- pointed to the position, and the collections are already feeling the benefits of an increase in the power of dealing with accu- mulated arrears. Visits of Naturalists. The annual visit of members of the Council of the Ento- mological Society of London took place on July 2-4. There were present—the President, Professor E. B. Poulton, the Vice-President, Dr. F. A. Dixey, D.M., Wadham College, the Secretary, Mr. H. Rowland-Brown, M.A., University College, and the following members of Council :—Mr. J. E. Collin, Mr. Hy, Hs: Druce,, Mr. W, J. Lucas; and Mr. A.J. Chitty, MEAs Balliol College. The following ex-Presidents of the Society 5 were also present :—Mr. Roland Trimen, Hon. M.A., F.R.S., Professor Meldola, F.R.S., Mr. G. H. Verrall, together with Mr. Horace Donisthorpe and Mr. M. Jacoby. The Proctors, Dr. F, A. Dixey, and the Professor represented the Hope Curators. Commander J. J. Walker and Mr. W. M. Geldart, M.A., Trinity College, kindly helped to render the visit a success. As on previous occasions, much work was compressed into a brief space of time, and the University collections have benefited in many ways. The Department has been visited in the course of the year by many naturalists who have helped in its increase and development. They have thus been enabled to some extent to see the use which has been made of the specimens they have presented and the value that is attached to them. In some cases, however, they have come to do some definite piece of work, and had but little time to spend in seeing the collection. Thus, Mr. G. A. K. Marshall made two or three visits, but worked hard at the African Coleoptera in the Burchell Collection, and had little opportunity of inspecting the immense numbers of specimens presented by him, the brief description of which fills no inconsiderable part of these yearly Reports. It was a great pleasure to show Mr. C. A. Wiggins on more than one occasion the wonderful series of butterflies collected by him at various points around Lake Victoria Nyanza, and to show Mr. Horace A. Byatt, B.A., Lincoln College, the valued specimens sent by him from British Central Africa. Colonel J. W. Yerbury, so far as time permitted on a brief visit, looked through the British Collection of Diptera, of which he has given by far the larger part. Mr. H.S. Glad- stone, who collected the Bahama specimens so much valued in the Hope Museum, visited the Department, unfortunately at a time when the Professor was away from Oxford. Miss Dorothea M. A. Bate gave valuable information concerning the specimens from Cyprus presented in Ig03. Mr. W. J. Lucas similarly rendered kind assistance in the elucidation or ampli- fication of data accompanying the specimens given by him, and in naming British specimens in the groups of which he 6 has made a special study. Mr. Roland Trimen, F.R.S., Pro- fessor Meldola, F.R.S., and Mr. Hamilton H. Druce in the course of their brief visits had but little time to see the valuable material they have presented to the Hope Museum. The Department has also been visited by the following naturalists :—Professor A. Giard, of Paris, Professor Monticelli, of Naples, Miss E.M. Sharpe, Mr. N. Annandale, Deputy Super- intendent of the Indian Museum, Calcutta, Mr. Willoughby Gardner, Mr. J. R. Hardy of the Manchester Museum, Mr. G. C. Champion, Mr. Selwyn Image. Dr. Comté, Naturalist of the “ Laboratoire des Soies,” Lyon, came to Oxford in order to study and draw some of the West- wood types of the silk-producing moths. Work done by the Staff. The arrangement of the general collection of butterflies has been continued by Mr. W. Holland, who has finished another family, the Evycinidae. He has also arranged the MWembra- cidae and allied groups of the Homoptera. In this latter work the greatest assistance was afforded by the preliminary classification of the material and the names given by Canon W. W. Fowler, D.Sc., Jesus College, as well as by the work of Mr. G. B. Buckton, F.R.S., upon a large proportion of the Hope Membracidae. Type labels have lately been added to all the specimens described in his “ Monograph of the Mem- bracidae.” Much of Mr. Holland’s time has also been occupied in incorporating the accessions, and in examining the Coleoptera for types and carefully labelling them when found. A large amount of labour was also expended in separating the Burchell specimens from the general collection and in searching for them in other directions. Both Mr. Holland and Mr. Hamm have also continually assisted in the various pieces of special work and researches of every kind which have been carried on in the course of the year. The largest single piece of work undertaken by Mr. A. H. 7 Hamm during the year has been first supplying printed labels of locality, date, and specific determination to the extensive series of British Diptera presented by Colonel J. W. Yerbury, and then arranging these with the accessions of earlier years in the order of Mr. Verrall’s list of British Diptera. The collection thus arranged occupies 45 drawers in one of the old but excellent Standish cabinets. It is a great satisfaction to know that the material in this important but difficult and insufficiently studied Order is in a condition to afford assistance to the student. With this extensive piece of work and with the large amount of printing, cataloguing, and manipulation required by other accessions, Mr. Hamm has had but little time to devote to the older part of the collection, with the exception of the Burchell specimens, which have received considerable attention. He was, however, able to give part of a few weeks to the resetting of a portion of the Nymphaline butterflies in the general collection. Southern Butterfly Faunas. The development of the collections described below is not entirely new, for the Wollaston Canarian and Madeiran beetles, &c., have always been kept apart. It is hoped ultimately to create these collections for other special localities, principally islands, and to include other Orders as well as the Lepidoptera and Coleoptera. The kindness of Commander Walker in presenting to the Department a fine series of insects from New Zealand and temperate South America, together with a favourable oppor- tunity of acquiring a number of Lepidoptera from the Patagonian Andes, made it possible to form the nucleus of two special collections of butterflies, possessing remarkable interest in relation to the problems of geographical distribu- tion. The great importance of such collections is at once realized when it is remembered that the instructive lacunae in the fauna are thus displayed at a glance. Omitting three probable stragglers, Anosta archippus, Hypolimnas bolina, and 8 Funonia vellida, only twelve species of butterflies are known in New Zealand. Three are NVymphalinae, the cosmopolitan Pyramets cardui (the well-known “ Painted Lady”), and two species of the same genus allied to our own “ Red Admiral” (P. atalanta), viz. P.itea,common to Australia, and P. gonerilla, the “ New Zealand Admiral,’ a remarkable form peculiar to the group of islands. Four are Satyrinae, belonging to two peculiar genera, and a third which may be peculiar but is certainly very near the northern Hredza. Five are Lycaenidae (‘ Blues” and “Coppers’”’). The affinity of the assemblage as a whole is distinctly northern. In fact there is no southern affinity, except in the Pyramezs ztea, which being identical with the Australian species, is probably either migratory or a recent accession. Such a collection at once compels the attention to the groups which are wanting. The absence of tropical families like the Danainae (except for A. archippus) and Acraeinae is not to be wondered at, but there is the surprising absence of all Pzerinae (“Whites”), Papilioninae (“Swallow-tails”), and, still more astonishing, Hesperidae (“Skippers”). Stupendous problems concerning the past history of the world are raised by a glance at this little collection, problems which are barely suggested by the separate units scattered here and there, according to their zoological affinity, throughout a vast general collection of about 60,c0o specimens. They are, however, needed in the general collection for another purpose, for the study of the precise affinity of each species by comparison with its nearest allies wherever they may be found. Thus two sets of speci- mens are required from localities with such special interest. Owing to Commander Walker’s kind help, the special New Zealand collection contains 10 out of the 12 species, while the general collections contain a fine series of several of the species. The absentees from the former collection are P. cardui and one Lycaenid, both of which can probably be obtained without great difficulty. The case of New Zealand has been treated in some detail, in order to demonstrate clearly the stimulus to thought which 2 it is hoped may be supplied by this extension of the Univer- sity Collections. The butterfly fauna of the Chilian and Patagonian Andes is equally interesting. There, cut off from the northern land- belt by the whole width of the tropics, is an assemblage of species almost wholly northern, and strongly northern, in affinity. This is not the case in Tasmania, the mountains of Natal or of the Cape Peninsula. It may well be that the explanation is to be found in the north and south trend of the great ranges of the New World as compared with their east and west trend in the Old. Thus a highway, or at least stepping-stones, may have been provided for the journey of northern forms across the American tropics, while the inducement to set out may have been given by the push of the advancing ice of the Glacial Period. Such hypotheses, suggested bya glance at these collections, become the stimulus for further investigation :—for example, in the study of this particular problem, the attempt to discover how far isolated northern communities still linger at great heights in favoured spots scattered through the Andes within the tropics. Assistance in working out the material in the Department. Commander Walker has worked in the Hope Department nearly every day since he first came to reside here in May of last year, on his retirement from active service. He has helped in the kindest manner in a great variety of pieces of work—in naming and arranging the fine collection of butterflies from Macao, presented by Mr. J. C. Kershaw, from Siam by Dy Richard» Evans; D.Sc.; M.A.; Jesus Collese;-and the Burchell Collections of British Lepidoptera and Coleoptera. The latter specimens he not only determined but restored with such skill that, after nearly 100 years and at times very severe treatment, the great majority are converted into excellent specimens. Among the other Orders in Burchell’s British Collection the Diptera have been determined by Col. J. W. Yerbury, Mr. 10 G. H. Verrall and Mr. J. E. Collin, the Neuroptera by Mr. W. J. Lucas and Mr. Kenneth J. Morton, the Hymenoptera Aculeata by Mr. Edward Saunders, F.R.S., and the Zeuthredinidae by the Rev. F. D. Morice. Dr. G. B. Longstaff, D.M., New College, visited the Depart- ment many times in the year, and undertook here the chief part of his researches upon the fine collection of over 2,000 insects of various Orders—chiefly butterflies—made by him (1903 and 1904) in India, Ceylon, S.E. China, Japan, and Canada, and presented to the Department. Dr. Longstaff communicated his memoir to the Entomological Society of London in December last. The manuscript is now going through the press. When Mr. Guy Marshall was in England in 1902 he was preparing his great monograph on the African Curculionid genus //zpporrhinus. On the occasion of one of his visits to Oxford he examined and named nearly the whole of this group of beetles in the University Collection. There remained, however, 15 specimens which he could only study satisfac- torily by comparing them with his own collection in Salisbury, Mashonaland. He took these weevils with him for this pur- pose, and they have recently come back in safety. One species was found to be new, and is described in his monograph as Hipporrhinus oneili. It is represented by 2 males and 1 female (the type), bearing the data “ Natal, Colenso, 1880,” Of the 12 remaining specimens 9 belong to known species and are now determined, while 3 of a single species are con- sidered by Mr. Marshall to be perhaps Australian. In any case their condition renders a description inexpedient. Colonel Yerbury’s remarkable success in discovering a large fly, Callicera yerburyt, Verrall, new to science, during his visit to Scotland in the summer of last year, led to a critical exam- ination by Mr. G. H. Verrall of all the available specimens of the genus to be found in collections throughout the country. Colonel Yerbury with great kindness came down to Oxford on purpose to search for examples of Cad/ccera in the University Collection of Diptera. As a result, there has been brought to 1g light a single Mexican specimen which Mr. Verrall pronounces to be the at present unique representative of another new species. The large amount of material in the difficult Nymphaline genus Azaca has been named and arranged by Mr. Herbert Druce, FES. Many Lycaenid and Hesperid butterflies from various parts of the world have been determined by Mr. Hamilton H. Druce, F.L.S., to whom is owing the satisfactory condition of the former large and difficult family. Dr. A. Senna, of Florence, has, as in previous years, given the kindest assistance in difficulties with the Brenthridae ; Mr. Edward Saunders, F.R.S., with the Palaearctic Hymenoptera Aculeata and Hemiptera; the Rev. F. D. Morice with the Teuthredinidae and Chrysididae ; Col. J. W. Yerbury with the Diptera ; Mr. M. Jacoby with the Coleoptera Phytophaga. Much kind assistance is especially acknowledged in the succeeding section of this Report, which deals with the work expended upon Burchell’s foreign collection. Editing W. F. Burchell’s notes for publication and working out the corresponding parts of his collection. In the Report of last year the hope was expressed that Burchell’s manuscript notes might be printed, so that the burden of constant reference should not be “thrown upon the original manuscript, which is a priceless possession.” .. . ““Then, as each paper appears, describing some part of the great collection, every naturalist could compare it with an authentic copy of the geographical notes, dates, and records of observations made by the naturalist whom Oxford honoured with the degree of D.C.L. in 1834.” Not long after the time when these words were written, the opportunity for carrying out this much-needed work arose, and the copy of Burchell’s manuscript was begun on May 19, 1go4. If the original programme had been adhered to the work would probably have been published before the end of the same year; for it 12 was a comparatively simple matter to make an exact copy of the notebooks. But it very soon became clear that such a volume would lose nearly all its value if the specimens referred to in the notes were not found, determined, and when new described. Burchell’s African Catalogue is a complete account of the corresponding collection, and at first it was thought sufficient to determine the South African species and print the Brazilian manuscript as it stood. The latter only provides a complete record of his captures at the very begin- ning of the South American journey—between July 26 and Oct. 27, 1825. Beyond this latter date the notebook con- tains records (brought into relation with the specimens by numbers) “of such Insects o7/y as require special and particular remark’’—a very small proportion of the whole collection. However, these “special and particular” remarks are of the deepest interest to the naturalist, and it was soon realized that the specimens must, as far as possible, be recovered and determined. It was therefore decided to add the name of the species, wherever possible, to the observations, accompanied by reference numbers; but to print in their present form, without addition, those Brazilian notes referring to locality only. These are indicated by dates and not numbers. To find the corresponding specimens would be an immense labour ; for the vast bulk of the American collection is labelled with dates, and only a small proportion with numbers. And the gain would not be commensurate. To collect together, for example, the varied assortment of insects captured by Burchell, at Rio, on New Year's Eve, 1825, during an “ Excursion to the summit of the Corcovado; from Catete and up the Valley of Laranjeiros,” would be a pro- longed and difficult task. Moreover, as the collection is gradually worked out and published in separate memoirs these facts will emerge, and can easily be separated and brought out in a concluding paper. Hence, while admitting the interest and importance of collecting together these assemblages of forms observed on a single day and under the same conditions, it was thought better not to defer the 13 present work too long in order to include them, considering that they will appear at some later date. On the other hand, such an important observation as the following demands the deter- mination of the specimen referred to, when it can be found: “351 [Reference Number]. 1 [indicating a single individual]. 15th Oct., 1825. At the Discoberto do Antonio Velho [during a journey from Rio into Minas Geraes]. P.[meaning ‘ Papilio,’ in the wide sense]. This species and the following settle on the smooth sunny bark of the trunks of large trees, and when in their flight they meet another of the same species they appear to fight, and at the same time produce with their wings an extraordinary and loud and quickly repeated crack- ling noise.’ A specimen of the Nymphaline butterfly, Perz- dromia amphinome, L., bears the No. “351,” while “352” is borne by the closely-allied Peridromia feronia, Hiibn., the very species upon which Darwin made the same observation, a few years later, when visiting Rio, on the voyage of the Beagle, April 4 to July 5, 1832 (“Journal of Researches,” London, 1876, pp. 33, 34). It was therefore decided to attempt to find and determine every African specimen and every numbered specimen from other parts of the world, referred to in Burchell’s note-books. This has proved to be the hardest single piece of work under- taken in the Hope Department during the past twelve years. Nevertheless, it is hoped that the whole of the manuscript will be in the hands of the printers before May 19, 1905, in less than a year from the commencement. Such compara- tively rapid progress has only been possible by co-operation on a large scale, and it is a great pleasure to acknowledge the large amount of assistance which has been received in the course of this considerable undertaking. One rather extreme example will serve to indicate the kind and extent of labour which has been necessary, as well as the friendly sympathy of brother-naturalists. Entirely out of place in one of the two boxes containing Burchell’s British insects, was a very small pill-box containing —quite loose—nine minute beetles, each about the size of 14 a pin’s head. On the lid was written in Burchell’s handwriting, “ Habitat in Boleto C. G. 3179-2.” Inquiry at Kew revealed the fact that No. “ 3179-2” in the ‘“‘ Catalogus Geographicus ” of Burchell’s African plants was a Loletus collected in the “ Boschberg,” between Graaff-Reynet and Grahamstown, on the morning of June 5, 1813. It is likely that Burchell, ex- amining the African herbarium in his home at Fulham, found these beetles which he had accidentally brought in the fungus. Probably they were included in the British collection because they were thus found in England; for other insects with the same history were similarly placed. In spite of their precarious existence as specimens, exposed to injury every time the box was moved, the beetles looked wonderfully fresh after Commander Walker had_ skilfully cleaned and mounted them. Eight were a species of C7zs which Mr. Guy A. K. Marshall determined as Exnearthron cucullatum, of Mellié. The ninth was a puzzling species which he and Commander Walker placed in the genus Dorcatoma (Anobiidac). It was taken to the British Museum, and considered by Mr. G. J. Arrow to be a Scymunus, belong- ing to a very different family, the Coccinellidae. It was sent to Rev. H. S. Gorham, at Southampton, and then to Dr. David Sharp, F.R.S., at Cambridge, who decided in favour of the first determination. Finally the beetle was dispatched to Monsieur Maurice Pic, of Digoin, Sadne-et- Loire, who pronounced it to be a new species which he has described for the present work under the name of Dorcatoma burchell. The clerical part of the undertaking was lightened by the fact that the Professor had already in 1903 made a copy of most of the Brazilian note-book. In finishing this and the Brazilian Itinerary and in the first part of the African Catalogue, Commander J. J. Walker rendered much kind help in writing, and in reading the original for copying and for verification. Miss C. B. Sanders, of Lady Margaret Hall, also kindly assisted in the verification of the Brazilian copy. Mr. Guy A. K. Marshall, during his visit to England in the 15 summer of 1904, wrote out the whole of Burchell’s collation of his African insects with the Banks collection and of the African beetles with Olivier’s “ Entomologie.” He also, with the Professor, verified this and the copy of the whole African Catalogue and part of the Brazilian. With his efficient aid the whole of the immense mass of dates and the numerous localities, arranged, according to Burchell’s classification of his specimens, in the African Catalogue, were again copied and redistributed to form an African Itinerary, into which were inserted the Insects, Arachnids, &c., captured upon each day. A critical comparison of this naturalist’s diary with the original Catalogue was the means of detecting a few mistakes made by the most accurate and painstaking of observers. In nearly every case the nature of the error was obvious. and in all the correction is probably right. The construction of an African Itinerary was greatly aided by the kindness of the Radcliffe Librarian, Dr. W. Hatchett Jackson, D.Sc., Keble College, who permitted the removal of Burchell’s “ Southern Africa,” in order that the map might be studied and repro- duced. The copy of Burchell’s work in the Hope Library is unfortunately imperfect, wanting both plates and map. The great labour of searching through the collection for the Burchell specimens has fallen almost exclusively upon Mr. W. Holland. Large numbers of the African moths and Orthoptera have been entirely destroyed by various pests, but fortunately Burchell left the reference numbers still fixed to the pins, so that the former existence and disappearance of the specimens was attested and no further search was necessary. Such evidence barely exists in the Brazilian collection, and yet many hundreds of specimens are absent, especially during the earlier part of Burchell’s residence at Rio. Therefore each missing specimen was necessarily searched for again and again until its absence appeared to be certain. Fortu- nately nearly all the interesting observations were made later, and the great majority of the specimens to which they refer has been found. But it is very remarkable that a much larger proportion, in fact a very high proportion, of the smaller, 16 older (1810-15), more battered African specimens should be accounted for, than of the comparatively fresh material in the younger (1825-30) and far larger Brazilian collection. A very valuable catalogue of the whole collection made, soon after its arrival in Oxford, under the direction of Professor Westwood, and in part by his own hands, has been and will be of the utmost assistance in determining how far the Brazilian collec- tion was complete when it reached Oxford (Ann. Mag. Nat. Hist. 1904, p. 306). Professor Westwood took the keenest interest in the Burchell Collection and appreciated the immense value of its geographical data, of which he showed the importance in a paper read before the Ashmolean Society on Nov. 26, 1866 (see “ Proceedings,” also Ann. Mag. Nat. Hist., 1904, pp. 307, 308). Although he only determined a small proportion of the species, many of those which he studied were obscure and difficult, and his identifications have been of the utmost value in the present work. Much assistance has been rendered in the search by the presence of a large printed “ Burchell Coll.” label affixed to the specimens in Oxford, but for this very reason the small proportion without this label was extremely hard to find. Thus several very important African specimens bore a smaller label with the same words in the handwriting of Professor Westwood. Some few had no label at all except Burchell’s reference number, which being small was generally concealed by the insect itself. The difficulty was rarely increased by actual mistakes or transpositions. One of the ants referred to and figured by Burchell (“Southern Africa,” London, 1822, pp. 448, 449) was labelled “China,” but the mistake was easily demonstrated by the reference number, the determination of the species and the character of the pin. All Chinese specimens in Burchell’s possession (none captured by himself) were transfixed by needles. Almost the only mistakes made in Oxford occur among the African butterflies and moths; and they are easily accounted for. When the collection arrived in 1865, the bodies of many of these insects had been eaten away, and the wings, often in a fragmentary condition, 17 were evidently lying about in more or less close proximity to the pin bearing the reference number. The wings were then brought into sets and gummed to pieces of card, on the under sides of which are to be found references to Con- vocation and other indications of University life. But in assigning these sets of wings to their reference numbers mistakes were occasionally made, and they could only have been avoided by the means which have now availed to set them right in, it is hoped, nearly every case—viz. by a critical comparison with Burchell’s African Catalogue. This was written before 1825, when the specimens were in com- paratively good condition ; and it represents the arrangement of individuals into species by a man with the intense interest of a naturalist and the eye of an artist. The separation into what he considered to be species is clearly shown; the reference numbers of additional individuals of the same form being always “inset” to the number of the first individual. Not only have errors been corrected by this means, but species have been determined from the most hopeless fragments. For example, a part of a patternless hind wing (right side) of a small moth was found still attached to the reference number “1209.” The catalogue showed this number, “inset ” to “1208,” borne by a moth still quite recognizable as the Pyrale, Glyphodes untonalis, Hiibn. Another source of difficulty and loss of time has been due to the fact that the specimens were so widely scattered :—great numbers in the duplicates disposed in various directions ; the majority in the appropriate parts of the general collection, relatively few, but still a large number, in the wrong parts of it; many hundreds never incorporated at all, but kept separate in old boxes and in parts of three very old cabinets, Three of Burchell’s original boxes were found untouched, two containing his British Collection and one the duplicates of his African Collection. A great many of the Lisbon specimens were found, probably untouched, in a similar box, but others had been incorporated. In many cases specimens which illus- trated each other were found in entirely different places. Thus € 18 various nests of Hymenoptera were exhibited in the small “show-cases” on the parapet of the gallery, while the bees and wasps which had constructed them were found in some one of the directions indicated above. This sketch suggests the nature and the amount of labour —chiefly borne by Mr. Holland—which was necessary in order to disentangle one very large collection from another vast collection. A large amount of work has also been thrown upon Mr. A. H. Hamm by the state of the specimens, hundreds of which required to be mended and repinned before they could be safely moved and studied. Great age and partial, sometimes nearly complete, destruction by the worst forms of pests combined to render the task of manipulation extra- ordinarily delicate and difficult. The success achieved by Mr. Hamm is more complete than could have been hoped. As the work proceeded it was often necessary to obtain evidence upon the handwriting of Professor Westwood at different periods of his life and seek information as to methods pursued, assistants employed, &c. In all such inquiries the Professor has invariably received the kindest and most efficient help from his friend, Miss Swann. The interpretation of Spanish and Portuguese words in the Brazilian manuscript would have been a great difficulty but for the kindness of Senor Don Fernando de Arteaga. Many of the data which have now happily been recovered could not have been obtained but for the sympathetic help of the Director of the Royal Gardens at Kew. Burchell’s vast botanical collections and the manuscript notebooks referring to them are in the Kew Herbarium, and many a: date and locality of importance to the collection of insects could only be decided by inquiry at Kew. Furthermore, it was most desirable to add the recognized specific names to the plants mentioned by Burchell in the records of insects, &c., captured on his two great journeys. Botanical names which are not now accepted occur frequently ; but through the kind- ness of Sir W. Thiselton-Dyer and the staff of the Herbarium, the fullest information which could be obtained has been 19 provided. It is hoped that the appearance of the volume, with the full Brazilian Itinerary, stated by Burchell to be intended for the Botanical no less than for the Zoological Collections, will confer some benefits upon students in the great botanical centre of the empire. It is in like manner a great pleasure to reflect that the appearance of this work will benefit the British Museum of Natural History, whose staff has so greatly aided in its pro- duction. Burchell gave large numbers of his African dupli- cates, indicated by an L. in his catalogue, to Dr. Leach for the British Museum. A large proportion of these can be found in the collection ; several have become the types of new species, several have never since been obtained. Yet the data are wholly wanting. By the publication of Burchell’s catalogue, the fullest data of time and space and circumstance will be available for many of these, and something can be learnt about all of them. Furthermore, the whole study of insects will benefit from the recognition of the types of species de- scribed by Burchell himself, and by other naturalists, from the specimens in his collection. An example of the recovery of lost types suggests the kind of work which has been done, and indicates its usefulness. Gory and Percheron brought out their great monograph on the Cetoniadae (“ Rose-chafers” or “ Rose-beetles”) at Paris in 1833. Many species described in it are spoken of as “ from the cabinet of Mr. Hope.” Nearly all these are well-known types in the University Collections. There remained, however, a few species—two of them types—which have never been traced, and specialists in the group have vainly searched our collections for them. All but one bear names proposed in manuscript by Burchell, but attributed by Gory and Percheron to Hope. The French coleopterists state of the single excep- tion that their own name had been printed before they received Mr. Hope’s suggestion. A sentence in Burchell’s handwriting, written on a small slip of paper and gummed into his African note-book, explained the difficulty and revealed the missing types :—“ Six insects borrowed by Mr. Hope, 3rd February, C2 20 1832—for publication.” Then follow the numbers of the speci- mens, “ 365, 386, [3]79, 368, 369, 345.’ The insects with these numbers are Cefoniadae, bearing the names employed in the French monograph. The handwriting of the names is unlike that on any other Burchell specimen, but resembles the inscrip- tion in the copy of the monograph presented by Gory to Hope. A special peculiarity, which the two have in common, is the use of a small initial letter to capital names. Finally, Burchell’s names are twice misspelt in the monograph, and the same rendering appears on the specimens. The whole story becomes clear. Hope sent a number of his own specimens, together with six borrowed from Burchell, to help on the work of his French colleagues. Owing to some error on the part of sender or receiver, all were accepted as Hope’s, and all were therefore looked for in Hope’s collection, But Hope had returned the six specimens to their owner, and they only found their way to Oxford in 1865 with the rest of Burchell’s insects. We may conclude with confidence that the types of Gory’s and Percheron’s Pachnoda carbonaria and P. leucomelana— lost for over seventy years—are now recovered, together with other specimens described and figured in their monograph. Allusion has been made above to mistakes in the data recorded on the specimens; but considering the great age and inevitable manipulation of the collection, it is surprising that there are so few. In the vast majority of cases it is certain that the data are correct; and, again and again, confirmation is yielded by some character of the specimen itself. As an illustration, No. “1269” in the Brazilian Notebook refers to a wasp, of which “2 or 3 nests enveloped in cotton were brought from Carmo and the insect found on opening to-day, dead, having been unable [to] expand in the cotton. .. .” Dec. 4, 1828, When the specimen bearing “1269” was recovered, it was found that a little cotton fibre was still entangled in its limbs, while the wings were not properly expanded. Again, No. “651” in. the African Catalogue, placed last, unnamed, among the Longicorn beetles, bears 21 the record “Consocians cum Lyczs 78-87 in floribus.” Nov. 18, 1813, Uitenhage. The specimen bearing “651” is Am- phidesmus analis, a beautiful Longicorn mimic of an entirely different group of beetles, the Lyczdae (see Trans. Ent. Soc. Lond., 1902, pp. 515-518, and Pl. XVIII, figs. 1-10 (models) and 25 (the mimic)). Burchell had noted the association be- tween model and mimic more than ninety years ago. This kind of verification is most inspiring. The work of the great naturalist lives again as we read his words, and recognize in the very specimens of which he wrote the truth of his observa- tions. “The investigation of the collection and the study of the notebooks reveal the fact that Burchell was the superior of every other naturalist in the preservation and labelling of material so that the record of his observations could be tested with scientific accuracy. It is a great pleasure to acknowledge all the kind help recelved from colleagues in many lands. In order to show clearly the part taken by each distinguished authority, the groups of insects are arranged below in the order adopted by Burchell in his African Catalogue. It is perhaps unnecessary to state that an arrangement followed before 1825 would not be followed to-day. Families, &c., which are referred to in the Brazilian Notebook alone are inserted among the African groups. The localities where the insects, &c., were captured are, as far as possible, considered in the order in which they were visited :—South Africa (1810-15), Portugal (April 2 to May 23, 1825), Teneriffe (June 2, 1825), the voyage to Rio (captures made on the “ Wellesley,’ June 12 and July 6, 1825), Brazil (July 26, 1825 to March 18, 1829). The Brazilian journey did not come to an end until Feb. 10, 1830, but the notebook containing Burchell’s observations after March 18, 1829, is most unfortunately missing. (See Ann. Mag. Nat. Hist., Feb. 1g04, p. 98, and April 1904, p. 309.) COLEOPTERA, Cicindelidae and Carabidae. AFRICAN AND BRAZILIAN,— G. J. Arrow. 22 CERTAIN SPECIES,—Dr. W. Horn, of Berlin, Guy A. K. Marshall, C. J. Gahan. Dytiscidae. AFRICAN,—Guy A. K. Marshall. BRAZILIAN,—Dr. David Sharp, F.R.S. Buprestidae. A¥RICAN,—J. J. Walker. CERTAIN SPECIES,—C. O. Waterhouse. Throscidae, BRAZILIAN,—G. J. Arrow. Elateridae. A¥RICAN,—Guy A. K. Marshall. BRAZILIAN,—C. J. Gahan. Cyphonidae. BRaAzILiAN,—G. J. Arrow. Lycidae, Lampyridae, and Telephoridae, AFRICAN AND BRAZILIAN,—Monsieur Jules Bourgeois, of Ste. Marie-aux- Mines [Markirch], including the description of four new species in Ann. Mag. Nat. Hist., 1904, Feb., pp. 89-102, and two in the present work. Melyridae. A¥RICAN,—J. J. Walker. Cleridae. AFRICAN AND BRAZILIAN,—J. J. Walker, Guy A. K. Marshall, C. J. Gahan. CERTAIN DIFFICULT SPECIES,—Rev. H. S. Gorham. CLAVICORNIA. AFRICAN AND BRAZILIAN,—G, J. Arrow. CERTAIN OBSCURE BRAZILIAN SPECIES,—Monsieur A. Grouvelle, of Issy-les-Moulineaux, Seine. fFTisteridae. BRAzILIAN,—George Lewis, F.L.S. Passalidae. BRAzILIAN,—G. J. Arrow. LAMELLICORNIA. AFRICAN AND BRAZILIAN, —chiefly named by G. J. Arrow, who also described one new African species. The African Lamellicorns were also care- fully studied by Guy A. K. Marshall, who named many species unrepresented or incorrectly determined in the National Collection. A few of the most difficult were taken by him to Cape Town, where further kind help was rendered by L. Péringuey. Assistance in special difficulties in the Cetoniadae was kindly rendered by O. E. Janson. 23 In this group the history of British Museum types has been made clear. The type of Burchell’s Aphodius ve- Sspertinus (with co-types in the British Museum), and six specimens described by Gory and Percheron (two of them types) have been recovered. HIETEROMERA. AFRICAN AND BRAZILIAN,—chiefly named by C. J. Gahan. Much assistance was also rendered by G. J. Arrow, and, in the case of the African species, by Guy A. K. Marshall, in the American by G. C. Champion. Further help with a few of the most puzzling African species, taken to Cape Town, was given by L. Peéringuey. Burchell’s type of JZoluris vialis (with co-types in the British Museum) was recovered. Anthribidae, AFRICAN AND BRAZILIAN,—Dr. Karl Jordan. Brenthidae, A¥FRICAN,—Guy A. K. Marshall. BRAZILIAN,—C. J. Gahan. Curculionidae, A¥RICAN,—Guy A. K. Marshall, including the description of three new species after comparison with his collection in Salisbury, Mashonaland. Assistance was also given by J. J. Walker and G. J. Arrow. BRAZILIAN,—G. J. Arrow, C.O.Waterhouse, G. C.Champion, and J. J. Walker. Ptinidae. BRAZILIAN,—J. J. Walker. A nobiidae, AFRICAN (one specimen of a Dorcatoma and one of a Zheca),—both new, and described by Monsieur Maurice Pic, of Digoin, Saéne-et-Loire. Opinions upon these puzzling little beetles were also kindly given by Ja yw«Walkes Go J; Arrow, Rev. H. S. Gorham, and (Dr; David Sharp. Bostrichidae. A¥FRICAN,—Monsieur P. Lesne, of the Museum d’ Histoire Naturelle, Paris, who described one new species. Assistance was also rendered by C. J. Gahan. Crotdae. A¥FRICAN,—Guy A. K. Marshall. Bruchidae. A¥RICAN,—One puzzling species studied by Guy A. K. Marshall, J. J. Walker, W. F. H. Blandford, David 24. Sharp and P. Lesne. It was finally placed in or near the genus Urodon. LoweicorniéA. A¥RICAN,—Karl Jordan. Kind help was also rendered by Guy A. K. Marshall and C. J. Gahan. The latter described two new species. BRAZILIAN,—C. J. Gahan. Casstdidae. A¥FRICAN,—Guy A. K. Marshall. BRAZILIAN,—C. J. Gahan, G. J. Arrow, C. O. Waterhouse. Puyrornaeéa (exclusive of Casstdidae and Fispidae). AFRICAN AND BRAZILIAN,—M. Jacoby, who not only determined the large numbers of species, but described two that were new. Help was also given by C. J. Gahan. fTispidae, BRAZILIAN,—C., J. Gahan, G. C. Champion. Endomychidae and Erotylidae. BRAzILIAN,—G. J. Arrow. Coccinellidae. AFRICAN AND BRAZILIAN,—G. J. Arrow. An African species not in the British Museum was studied by Guy A. K. Marshall, and finally named by Rev. H. S. Gorham, who also kindly determined a few of the more difficult American forms. Larvae of CoLzOPTERA. BRAZILIAN,—Lampyrid larvae were studied by Jules Bourgeois, and two interesting and difficult forms by C. O. Waterhouse. COLEOPTERA. PORTUGUESE AND CANARIAN,—J. J. Walker. Assistance was also rendered by Monsieur Jules Bourgeois, G. C. Champion, G. J. Arrow, C. J. Gahan, and Canon W. W. Fowler. ORTHOPTERA: ALL LOCALITIES,—W. F. Kirby, Guy A. K. Marshall (African species only). OBSCURE AND DIFFICULT SPECIES,—Senor Don Ignacio Bolivar, of Madrid, who also gave advice on questions of terminology, &c. 25 RHYNCEOPA-IEMIPTERA. AFRICAN AND BRAZILIAN,—W. L. Distant, Guy A. K. Mar- shall (African species only). CERTAIN BRAZILIAN SPECIES,—G. C. Champion, Edward Saunders, F.R.S. PORTUGUESE SPECIES,—Edward Saunders, F.R.S. NiiyNeCHOrA- HOMOPTERA. ALL LOCALITIES,—W. F. Kirby, Guy A. K. Marshall (African species only). CERTAIN SPECIES WHICH OFFERED SPECIAL DIFFICULTY,— We Distant. PEPIDOP LER. PORTUGUESE AND CANARIAN,—W. Holland, A. H. Hamm. EEPIDORTERA-REHOPALOCE RA. The whole of the butterflies, both African and American (with the exception of the Lycaenidae, Picrinae, and Hespe- vidae), had been dealt with in the course of the determination and arrangement of the whole Collection by W. Holland, of the Hope Department. The Burchell Rhopalocera have been confirmed, with modification in certain cases of special diffi- culty, by the following specialists : AFRICAN,—Roland Trimen, M.A., F.R.S., who had deter- mined the Lycaenidae and Hesperidae many years previously. For the purpose of the present work he carefully re-studied them, and consulted with Hamilton H. Druce on special difficulties arising out of the fragmentary condition of some of the specimens. F. A. Heron also gave his opinion on special cases among the Satyrznae. Pierinae. A¥FRICAN,—F. A. Dixey, who had previously deter- mined the species, and had recognized in certain tattered 26 fragments Swainson’s type of Zeracolus subfasciatus and of the genus Zeracolus. Many obscure points were recon- sidered by F. A. Dixey for the purpose of this publication. LIthomiinae, Danainae and Satyrinae. BRaAziLIAN,— Cora B. Sanders, with the assistance in Oxford of W. Holland, and in London, of F. D. Godman, D.G.L., FikiS.08aee Heron and G. C. Champion. The most obscure and difficult 7thomiznae had been named several years ago by the late O. Salvin, F.R.S., and W. F. H. Blandford. NYMPHALINE GENUS Anaea. BRAZILIAN,—Herbert Druce. Lycaenidae. BRAZILIAN,—Hamilton H. Druce. Pierinae. BRAZILIAN,—F. A. Dixey. FHesperidae. BRAZILIAN,—F. D. Godman, D.C.L., F.R.S. OBSCURE BRAZILIAN SPECIES IN REMAINING GROUPS,—G. C. Champion, F. A. Heron, Karl Jordan, J. J. Walker. LEPIDOPTERA HETEROCERR AFRICAN,—Guy A. K. Marshall, J. J. Walker, A. H. Hamm. CERTAIN OBSCURE AFRICAN SPECIES,—Sir George Hampson kindly helped in the determinations. W. L. Distant was consulted upon a species described by him. Sphingidae. AFRICAN,—Dr. Karl Jordan. MiICRO-LEPIDOPTERA. A¥FRICAN,—J. Hartley Durrant. A new species was described by Lord Walsingham, F.R.S. Skins of Larvae. AFRICAN,—Lieut.-Col. J. Malcolm Fawcett, Sir George Hampson, Dr. Karl Jordan, G. F. Leigh, Guy A. K. Marshall, Roland Trimen, F.R.S. HETEROCERA ON VOYAGE TO RI0,—J. J. Walker. HIETEROCERA. BRAZILIAN,—W. Schaus. Sir George Hamp- son had previously described two new species. MiIck0-LEPIDOPTERA. BRAZILIAN,—J. Hartley Durrant. 27 NEUROPTERA. AFRICAN,—Guy A. K. Marshall and W.F. Kirby. The latter described a new genus, a species, and the female of an Aeschna. NEUROPTERA. BRAZILIAN—W. F. Kirby. MM ALLOPHAGA. BRAZILIAN,—E. E. Austen. HYMENOPTERA, AFRICAN AND BRAZILIAN,—Col. C. T. Bingham. Chrysididae,—Rev. F. D. Morice. ANTS,—Professor Auguste Forel, of Morges, who described one new species. Mutillidae,—Monsieur Ernest André, of Gray, Haute-Sadne. A NTHOPHILA (MANY SPECIES),—Dr. H. Friese, of Jena. Ichneumonidae (A SINGLE PORTUGUESE SPECIES),—Claude Morley, who also determined the genera of Brazilian species. PORTUGUESE A CULE ATA,—Edward Saunders, F.R.S.,who also gave advice upon the whole collection of Hymenoptera. DIPTERAt AFRICAN, PORTUGUESE, AND BRAZILIAN,—Col.J.W.Yerbury. CERTAIN SPECIES,—E. E. Austen, G. H. Verrall. Borboridae ON VOYAGE TO RI0,—J. E. Collin. ARACHNIDA ano MYRIOPODA. AFRICAN, PORTUGUESE, AND BRAZILIAN,—R. I. Pocock. BRAZILIAN CHELIFERS,—Dr. C. With, of Copenhagen. CRU S PAC Bake PORTUGUESE AND BRAZILIAN,—Dr. W. T. Calman. AN OBSCURE ISOPOD. BRAZILIAN,—Dr. Budde-Lund, of Copenhagen. 28 In addition to the invaluable assistance which—as it is hoped—is clearly set forth in the above statement, the attempt to trace the African specimens which Burchell gave away or exchanged has been aided by many kind friends. Of the numerous specimens given to the British Museum, a large proportion has been found. Mr. G. J. Arrow and Mr. C. J. Gahan helped in the search for them among the Coleoptera, Mr. W. F. Kirby among the Orthoptera and Neuroptera, Mr. W. L. Distant among the Hemiptera, Col. C. T. Bingham among the Hymenoptera, Mr. E. E. Austen among the Diptera. Dr. David Sharp, F.R.S., gave the information that a few specimens given to Professor Henslow, and a larger number given to Mr. Swainson, are not to be found in the University Collections at Cambridge. Miss Sulivan similarly states that specimens given to the late Mr. Stephen Sulivan, of Fulham, are not to be found. It is impossible sufficiently to emphasize the amount of help received from Mr. Guy A. K. Marshall in the preparation of the African section of the work. His remarkable knowledge of Southern Ethiopian forms has enabled him to confirm many doubtful determinations and correct many errors in the identi- fications. Mr. Marshall was also able to detect mistakes made by Burchell ; but since his return to Africa he has made further inquiry and conducted further observations, finding- that in some cases Burchell was after all right in his statements. The result of the whole critical examination to which Burchell’s manuscript and the corresponding parts of his collections have been subjected, is to produce the profound conviction that he was the most accurate of observers, His errors were almost invariably due to a want of technical zoological know- ledge in some special branch, so that he often placed his Brazilian insects in wrong groups. But such mistakes are easily set right and do not impair the priceless value of his observations on habits and his trustworthy registration of dates and localities. There is a wide difference between Burchell’s African and Brazilian Notebooks as regards these technical mistakes. The much smaller African collection 29 was most carefully studied and worked out by him in the interval between his return home in 1815 and his departure for Brazil in 1825. The immensely larger Brazilian collection was never studied in this way, and the names are merely the off-hand impressions of a naturalist abroad, without the materials or the time for study—a naturalist moreover who was a botanist far more than a zoologist, and a zoologist rather than an entomologist. But Burchell had a keen love for insects as well as for all other animals, and when he compared his African species with the Banksian specimens named by Fabricius, he worked with the critical insight of a trained and acute observer. The investigation of his con- clusions has made it clear that his interpretations are in some instances more correct than those which have since been adopted and have become the basis of existing terminology. The number of specimens tn various groups existing an the Hope Collection. I. LEPIDOPTERA AND COLEOPTERA. For many weeks Commander Walker has most kindly been at work upon a catalogue of the number of specimens in the Hope Collection. Members of the University have sometimes been astonished at the needs of the Department, and therefore it has been thought well to furnish a statement of the extent of the Collections at the present date. It is not possible to complete the list of all the Insect Orders in time for this Report; but the following statement is complete so far as it goes. The remainder of the list will appear in the Report of the present year. EE PIDOPTERA: EXOTIC RHOPALOCERA. Danainae, including . : ; 3 5727 specimens in 170 drawers [thomtinae Satyrinae . 3 : e 5370 ‘ LOOes 9%, LE lymniinae 2 eo a LOqe ms Morphinae and a eaenaHiie 922 a SORT ays I~ Acracinae . i : Loa! - AOn Sos 30 Nymphalinae, i i ae a } ASACY ss oo Erycinidae ; : - 2348 e Ans Ge Lycaenidae : : .- »57O4 ‘ 612 Puerinae . : ‘ . 10096 :. 300... ©; Papilioninae . ; 5 4294. ‘ 135 . Flesperidae : : . 3448 . LoS ae otal «x : - 55441 specimens in 1418 drawers Add™ : » 2194n Table Cases 32 reputed British » Grand Total . . 55086 Rhopalocera The collection includes the following special series :— Limnas chrysippus represented by 582 specimens Danats archippus Be LE ss flypolimnas Misippus 5 217 4 Hf. Bolina 216 s EXOTIC HETEROCERA. Sphinges— 1486 specimens in 57 drawers Heterocera other than Sphinges— 30642 specimens in 287 cab. drawers + 102 boxes Grand Total, 32128 Heterocera BRITISH LEPIDOPTERA. Rhopalocera . . 1613 specimens in 15 drawers Heteroceta’ ~ . 19800 bs 125 Ph Total ; . 21413 specimens in 140 drawers Add : - 3422 supplementary Heterocera Grand Total . 24835 specimens (British) Total of Lepidoptera : Drawers, Exotic . 55686 in 1418 Rhopalocera } British ~.-* TO, Ga) 56799 = 1433 Exotic . 232128 287 Heterocer f aN se chee Fs British --. 299g/27 55° 325 Grand Total. . 112149 ,, 1845+102 boxes dl COLE ORTERA. WOLLASTON COLLECTIONS. Canarian. : : : 5075 Cape Verde falas ‘ ‘ : = 146 St.ielena = F ; : : Sees fa Hotal:. : : : - : 5933 Madeira. ze : : : ~ 5528 Total, Wollaston Coleoptera . 11461 TYLDEN COLLECTIONS (exclusive of those incorporated in the general collection). Curculionidae 6680 Curculionidae, supp. 1800 Curculionidae 1945 Buprestidae 682 Total Tylden Coleoptera SLO? MIERS COLLECTIONS (exclusive of those incorporated). I; it. nie IV. Wis VI. Vil; Vile IX. X. XI. bu XIE. Cicindelidae . Carabidae Dytiscidae Hydrophlitidae Staphylinidae Clavicornia . Lamellicornia Buprestidae . Elateridae . Malacodermata Heteromera . Rhynchophora Anthribidae (now at Trade) Flispidae Total Miers Coleoptera 30 2505 194 206 ONE, 2191 4010 627 1084 noo 2704 6229 118 21956 32 GENERAL COLLECTIONS. Cicindelidae . : ; ; : 2 “3659 Carabidae. : : : : . 12166 Paussidae . : : : 258 Dytiscidae (including eS Yr ened » . 2080 Hydrophilidae : : : : , » Sarz06 Staphylinidae : : : ; ; 2 Bong Clavicornia ; : : » 1 73090 Lucanidae and / eae : ; - “T1746 Cetoniadae . . '3grg Lamellicornes (other Jon Ce iudne 19124 Buprestidae . : : : : Pra yc, Elateridae . : : : - 3006 Malacodermata . ; . ; 5. 20K Fleteromera . 5 ; ; : Eaaae Rhynchophora : . : ; y EEGs Longicornes . : . : ' . 14690 Phytophaga . ' : : ; . 18637 Total General Collection of Coleoptera 120423 Wollaston . pan . » RIg6a sixiiclenaar: bs . ; : , ige7 Miers . : : d « S21956 British ; A . ° » 29487 Grand Total of Coleoptera . 194434 Thus the Lepidoptera and Coleoptera are represented in the Hope Department by 306,583 specimens. Vork published in 1904. Mr. S. A. Neave, B.A., Magdalen College, left this country for Northern Rhodesia in January of last year. His paper on the large collection of Rhopalocera from the shores of the Victoria Nyanza, presented by Mr. C. A. Wiggins, was described in last year’s Report. It appeared in “ Novitates Zoologicae,” Vol. XI, March 1904, pp. 323-363. 33 Three papers on W. J. Burchell and his collections in the Hope Department appeared in the early part of 1904, and were described in last year’s Report. One part of a fourth paper on the first three sub-families of Brazilian butterflies, by Miss Cora B. Sanders, of Lady Margaret Hall, appeared in April, the second in May (Ann. Mag. Nat. Hist., pp. 305 and 356). An introduction and notes were contributed by the Professor, while Professor Westwood’s manuscript catalogue and notes were also incorporated. Commander Walker kindly aided in seeing these papers through the press, a task greatly increased by the immense number of dates and figures. The first important memoir on the Majorcan collection, made by Mr. Holland, Mr. Hamm, and the Professor in Igo1, was published in the course of the year, being an account of the Hymenoptera Aculeata by Mr. Edward Saunders, F.R.S. (Trans. Ent. Soc. Lond., 1904, pp. 591-665). The paper also included the Aculeates captured in Spain on the same expedi- tion, and by the Professor in 1902. In the mainland collection 205 species were recognized, in that from the island 143; but the latter included 5 species new to science—Pompilus poultont, Mimesa palliditarsis, Halictus hollandi, H. hammi,and H. dubi- tabilis. Of these, only the last-named occurs in the mainland list. The Professor contributed introductory accounts of the expeditions, notes on some of the species, and an Appendix on the mimetic resemblance borne by certain Diptera to the stinging Hymenoptera. The preparation of the paper and the correction of the proofs brought a great deal of work upon Mr. A. H. Hamm. The chief results of Mr. G. F. Leigh’s paper upon the breed- ing of Papilio cenea and Hypolimnas misippus have been already described (p. 18). The paper appeared in Trans. Ent. Soc. Lond., 1904, pp. 677-691. The Professor contributed notes, and Mr. Roland Trimen, F.R.S., an Appendix, on “ The merope- group of the genus Papilio.” The photographs from which the two very successful half-tone plates were executed were taken by Mr. Alfred Robinson. Major Manders’ paper on breeding experiments on Cavopsilia D 34 pyranthe, and notes on migration of butterflies in Ceylon (Trans. Ent. Soc., 1904, p. 701), also deals with the material of the Department, kindly presented by the author. Exhibitions of specimens belonging to the Department were made at the majority of the meetings of the Entomological Society of London throughout the year, accompanied by descriptive notes, which are published in the “ Proceedings.” The exhibitors and authors of notes were Dr. F. A. Dixey, Commander J... J.. Walker, Mr. G.cHe Verrall;y Drv tee Chapman, Col. J. W. Yerbury, Mr. G. J. Arrow, Mr. C. O. Waterhouse, Dr. G. B. Longstaff, and the Professor. The following short papers by workers in the Hope Depart- ment or upon its material have also appeared in the Proceed- ings of the same Society in the course of the year :—“ On the identity of the ‘ Bugong’ used as an article of food by the natives of Australia,” by Dr. F. A. Dixey; “A possible ex- planation of insect swarms on mountain-tops,” by the Professor; “The oviposition of Vanessa urticae,’ by Mr. A, H. Hamm ; “ The courtship of Vanessa urticae,”’ by the Professor ; “ Erebia evias, var. penalarae, and E. stygne, var. peralarae,” by Dr. T. A. Chapman; “ The scent of male Pierine butterflies,” by Dr. F. A. Dixey ; “ Pieris rapae seeking white flowers as a resting site,” by Mr. A. H. Hamm. Dr. G. B. Longstaff’s memoir, now in the press, has already been referred to on p. 26. In addition to the above list of papers and those published in last year's Report, there are two Presidential Addresses delivered to the Entomological Society of London by the Professor—in 1904, “What is a species?”; in 1905, “The bearing of the study of insects upon the question ‘Are acquired characters hereditary ?’.’ It will, therefore, be seen that the materials for the issue of a fifth volume of “ Hope Reports” are rapidly accumulating. ADDITIONS TO THE COLLECTIONS IN 1902. One thousand and ninety-one butterflies, 34 moths, 2 Hemiptera, 1 Asilid fly, 4 Hymenoptera Aculeata, including 35 a pair of Mutillids taken zz coztw, 7 Coleoptera, 19 Neuroptera, and r Orthopteron were presented by Guy A. K. Marshall, Esq. The specimens were captured in the following localities in Natal:—Estcourt, 4—5000 ft. (1896) ; Niginya, Ulundi, near Estcourt (5,800 ft.), and Ulundi (5,coo ft.); Tugela River, near Weenen, 2,500 ft. and 4,000 ft. (1896) ; Weenen (1896) ; Chuga’s Hill, near Weenen, 4,000 ft. (1896); Loskop, Little Tugela River, 4,500 ft. (1896); Karkloof, 4,200 ft.; Frere, 3,800 ft. (1896); Port Shepstone, sea level (1897); Durban, and the following localities near it :—Berea, 500 ft. (1897); Malvern, 800 ft. ; Claremont, 200 ft. (1897) ; Northdene, 800 ft. (1897); Isipingo, sea level (1896); Sydenham, 400 ft. (1897) ; the Palmiet River. In addition to the above important accessions to the general collection the bionomic series owes to Mr. Marshall the fol- lowing additions, from Natal :—A magnificent Ichneumonid mimic of a Fossorial wasp (.Sa/ius) from Estcourt (Nov. 1896) ; 4 Asilid flies with their prey—a beetle (Malvern, Nov. 1902) ; a bug, a Cicada, and a species of Asilid smaller than its captor (all from Estcourt, Nov. 1902); a Chalcid parasite bred from the pupa of the Pierine butterfly, Belenots mesentina (Natal only). In 1896 Mr. Marshall conducted an interesting series of experiments upon Pierine and Nymphaline butterflies for the purpose of testing the power of climatic conditions (moisture and temperature) to produce the seasonal phases which are known to occur in nature. <= > 4 ‘ é ; ; F 7 y : a vs , @&e a hi a oe 9 i vee. vere ” ~ on ‘ > 5 is a Se ae ee 6 + . , PU | Tai r é "@' Bp’ is ADE soak, : whe? tim 54 rr é = ; & ,=—e jk MA i }