Pearls & Parasites

Part 1

PEARLS AND PARASITES

PEARLS & PARASITES

BY ARTHUR E. SHIPLEY OF CHRIST’S COLLEGE, CAMBRIDGE; M.A., HON. D.SC., F.R.S.

WITH ILLUSTRATIONS

LONDON JOHN MURRAY, ALBEMARLE STREET, W. 1908

TO MY SISTER

E. D. H.

PREFACE

Most of the following essays have appeared in the pages of the Quarterly Review, and I am greatly indebted to the editor and to the proprietor of that periodical for permission to reprint them. The article on ‘The Infinite Torment of Flies’ is an address I delivered before the British Association at Pretoria in 1905, and the eighth essay appeared in Science Progress.

As far as possible I have tried to avoid the use of long words, and thus escape the censure of recent critics in the Times; but I fear I have not altogether succeeded, and my excuse must be that with new discoveries new conceptions arise, and these conceptions require new names, or we cannot talk or write about them with any precision.

The essay dealing with zebras and hybrids was the first to be written, and appeared before the rediscovery of Mendel’s remarkable work, and must be regarded as a pre-Mendelian contribution to a subject which has recently, in connexion with the Deceased Wife’s Sister Bill, again aroused attention. Had it been written later the language and the attitude taken would have been modified by recent research.

In the inquiry into the aims and finance of Cambridge University--the only essay which does not deal with questions of economic zoology--I have had the great advantage of the collaboration of Mr. H. A. Roberts, the Secretary of the Cambridge University Association. But for his help I fear I should have lost my way in the intricate mazes of the University accounts.

For the care he has taken in making the Index, I owe thanks to Mr. G. W. Webb, of the University Library.

A. E. S.

CHRIST’S COLLEGE,

CAMBRIDGE.

March 10, 1908.

CONTENTS

PAGE

PEARLS AND PARASITES 1

THE DEPTHS OF THE SEA 16

BRITISH SEA-FISHERIES 42

ZEBRAS, HORSES, AND HYBRIDS 73

PASTEUR 101

MALARIA 129

‘INFINITE TORMENT OF FLIES’ 155

THE DANGER OF FLIES 174

CAMBRIDGE 183

Part 2

INDEX 217

LIST OF ILLUSTRATIONS

FACING PAGE

MATOPO 84

TUNDRA (AN ICELAND PONY), HER FOAL, CIRCUS GIRL (BORN 1898), AND HER HYBRID-FOAL, SIR JOHN (BY MATOPO), WHEN A MONTH OLD (BORN 1899) 86

ROMULUS 92

MATOPO 92

ROMULUS 96

FIG. 1.--THE PARASITE OF TERTIAN FEVER, HÆMAMŒBA VIVAX (ROSS). HIGHLY MAGNIFIED 136

FIG. 2.--VARIOUS STAGES WHICH THE PARASITE OF THE ÆSTIVO-AUTUMNAL FEVER, HÆMOMENAS PRÆCOX(ROSS), PASSES THROUGH IN THE BODY OF THE MOSQUITO ANOPHELES. MAGNIFIED 2,000 TIMES. AFTER ROSS AND FIELDING-OULD 136

FIG. 3.--FORMATION OF THE BLASTS OF HÆMOMENAS PRÆCOX (ROSS) WITHIN THE BODY OF THE MOSQUITO ANOPHELES. MAGNIFIED 2,000 TIMES. AFTER ROSS AND FIELDING-OULD 144

ANOPHELES MACULIPENNIS. MALE, IN CHARACTERISTIC ATTITUDE 146

ANOPHELES MACULIPENNIS. FEMALE 146

BIBLIOGRAPHY

‘Report to the Government of Ceylon on the Pearl-Oyster Fisheries of the Gulf of Manaar.’ By W. A. Herdman, F.R.S. Parts I. and II. Published by the Royal Society. London, 1904.

‘On the Origin of Pearls.’ By H. Lyster Jameson. Proceedings of the Zoological Society of London, 1902.

‘Aus den Tiefen des Weltmeeres.’ By C. Chun. Jena: Gustav Fischer, 1900.

‘Tierleben der Tiefsee.’ By O. Seeliger. Leipzig: Wilhelm Engelmann, 1901.

‘Report of the Scientific Results of the Voyage of H.M.S. Challenger.’ Edited by the late Sir C. Wyville Thomson and John Murray. A Summary of the Scientific Results. Published by Order of Her Majesty’s Government, 1885.

‘La Vie au Fond des Mers.’ By H. Filhol. Paris: G. Masson, 1885.

‘The Fauna of the Deep Sea.’ By Sydney J. Hickson. London: Kegan Paul, Trench, Trübner and Co., 1894.

‘British Fisheries: their Administration and their Problems.’ By James Johnstone. London: Williams and Norgate, 1905.

‘An Examination of the Present State of the Grimsby Trawl Fishery, with Especial Reference to the Destruction of Immature Fish.’ By E. W. L. Holt. Journal of the Marine Biological Association, vol. iii. Plymouth, 1895.

Journals of the Marine Biological Association of the United Kingdom, vols. i.-vii. Plymouth.

‘Conseil Permanent International pour l’Exploration de la Mer. Rapports et Procès Verbaux,’ vol. iii. Copenhagen.

‘Fishery Board for Scotland. Report on the Fishery and Hydrographical Investigations in the North Sea and Adjacent Waters, 1902-1903.’ [Cd. 2612.] London, 1905.

‘Marine Biological Association. First Report on the Fishery and Hydrographical Investigations in the North Sea and Adjacent Waters (Southern Area), 1902-1903.’ [Cd. 2670.] London, 1905.

‘Annual Reports of the Inspectors of Sea-Fisheries for England and Wales.’ London, 1886-1905.

Part 3

‘The Penycuik Experiments.’ By J. C. Ewart. London and Edinburgh: A. and C. Black, 1899.

‘Experimental Investigations on Telegony.’ A paper read before the Royal Society, London, June 1, 1899. By Professor J. C. Ewart.

‘La Vie de Pasteur.’ Par René Vallery-Radot. Paris: Hachette, 1900.

‘Pasteur.’ By Percy Frankland and Mrs. Percy Frankland. (Century Science Series.) London: Cassell, 1898.

‘The Soluble Ferments and Fermentation.’ By J. Reynolds Green. (Cambridge Natural Science Manuals.) Cambridge University Press, 1899.

‘Micro-organisms and Fermentation.’ By Alfred Jörgensen. Translated by A. K. Miller and A. E. Lennholm. Third edition. London: Macmillan, 1900.

‘Lectures on the Malarial Fevers.’ By William Sydney Thayer, M.D. London: Henry Kimpton, 1899.

‘On the Rôle of Insects, Arachnids, and Myriapods as Carriers in the Spread of Bacterial and Parasitic Diseases of Man and Animals. A Critical and Historical Study.’ By George H. F. Nuttall, M.D., Ph.D. ‘Johns Hopkins Hospital Reports,’ vol. viii.

‘Instructions for the Prevention of Malarial Fever.’ Liverpool School of Tropical Medicine. Memoir I. Liverpool: University Press, 1899.

‘Report of the Malaria Expedition of the Liverpool School of Tropical Medicine and Medical Parasitology.’ By Ronald Ross, D.P.H., M.R.C.S.; H. E. Annett, M.D., D.P.H.; and E. E. Austen. Liverpool School of Tropical Medicine. Memoir II. Liverpool: University Press, 1900.

‘A System of Medicine, by many Writers.’ Edited by Thomas Clifford Allbutt, M.A., M.D., LL.D., vol. ii., 1897; vol. iii., 1897. London: Macmillan and Co.

‘A Handbook of the Gnats and Mosquitoes.’ By Major George M. Giles, I.M.S., M.B., F.R.C.S. London: John Bale, Sons, and Danielsson, Limited, 1900.

‘Reports to the Malaria Committee, Royal Society, 1899 and 1900.’ By various authors. London: Harrison and Sons, 1900.

Proceedings of the Boston Society of Natural History, vol. xvi., 1874.

U.S.A. Department of Agriculture, Division of Entomology, Bulletin 4, new series.

‘Manchester Memoirs,’ vol. li., 1906, p. 1; Quarterly Journal of Microscopical Science, vol. li., 1907, p. 395.

‘Endowments of the University of Cambridge.’ Edited by John Willis Clark, M.A., Registrar of the University of Cambridge. Cambridge: University Press, 1904.

‘Report of a Meeting held at Devonshire House on January 31, 1899, to inaugurate the Cambridge University Association.’ Cambridge: University Press, 1899.

‘Statements of the Needs of the University.’ Cambridge: University Press, 1904.

‘University Accounts for the Year ended December 31, 1904.’ Cambridge University Reporter, March 17, 1905.

‘Abstracts of the Accounts of the Colleges.’ Cambridge University Reporter, February 10, 1905.

PEARLS AND PARASITES

Know you, perchance, how that poor formless wretch-- The Oyster--gems his shallow moon-lit chalice? SIR EDWIN ARNOLD.

Certain Eastern peoples believe that pearls are due to raindrops falling into the oyster-shells which conveniently gape to receive them.

‘Precious the tear as that rain from the sky Which turns into pearls as it falls on the sea,’

as the poet Moore writes. This belief is of ancient origin, and is probably derived from classical sources, since Pliny tells us that the view prevalent in his time was that pearls arise from certain secretions formed by the oyster around drops of rain which have somehow effected an entrance into the mantle cavity of the mollusc. Probably this theory of the origin of pearls has ceased to be held for many centuries except in the East, where tradition has always received more credit than experiment. In the West it has long been known that pearls are formed as a pathological secretion of the mineral arragonite, combined with a certain amount of organic material, formed by the oyster or other mollusc around some foreign body, whose presence forms the irritant which stimulates the secretion. This secretion is of the same chemical and mineralogical nature as the mother-of-pearl which gives the inside of the shell of so many molluscs a beautiful iridescent sheen.

An oyster-shell consists of three layers, the outermost termed the periostracum, the middle the prismatic layer, and the innermost the nacreous layer. Everywhere the shell is lined by the mantle, consisting of a right and left fold or flap of the skin, which is in contact with the nacreous layer all over the inside of the shell. The edge of the mantle is thickened and forms a ridge or margin; and it is this edge which secretes the two outer layers. This permits the shell to grow at its edge whilst the rest of the mantle secretes all over its surface the nacreous or pearly layer. The relative thickness of these three layers varies very greatly. In the fresh-water mussel (Unio) the nacreous layer is many times thicker than the two outer layers put together; and such nacreous shells are usually associated with molluscs which are known to represent very ancient or ancestral species. It is also the layer which disappears most readily as the specimens become fossilized; and in fossil Mollusca it is often represented by mere casts, which fill the position it once occupied.

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