As a subject of investigation the Trematode fauna of British Birds does not appear to have aroused at any time much enthusiasm amongst British zoologists and as a result we owe the greater part of our knowledge of the subject to continental workers. The fact that our bird fauna is practically identical with that of the adjacent parts of Western Europe would lead us to expect that the parasites of our birds should not differ materially from those met with in the same species of birds on the continent. As a matter of fact, no species of bird Trematode hitherto recorded from this country can be regarded as peculiar to Britain, with the possible exception of Echinostephilla virgula Lebour, which, however, will almost certainly be met with in other localities later.

The object of this paper is to develop the ideas put forward in previous publications (Duke, 1919, 1921).

Among material recently sent for identification by the Molteno Institute of Parasitology were a number of small Nematode worms collected by Mr E. A. Chapin from the rectum of the North American Tortoise, Cistudo Carolina.

It is well known that the ectoparasitic Arthropods often produce in their host various skin reactions such as macules, wheals and haemorrhages, which in many cases are due to the salivary secretion of these ectoparasites. Nuttall and Strickland (1908) were the first to find an anticoagulin (called “Ixodin” by Sabbatani) in the salivary glands and alimentary canal of Argas persicus. Bruck (1919) found that the organs of Culex contained a haemolytic- and urticaria-producing substance called by him “Culicin.” His study was not, however, precise, because he ground up the entire bodies of the gnats, thereby mixing up secretions, excretions and fragments of organs, some of which would never enter a wound in the process of blood sucking. Moreover, the urticaria following mosquito bite was found by Schaudinn to be due to the yeast present in the oesophageal diverticula of mosquito. Klausner (1916) states that the secretions of the salivary glands in Cimex are soluble in water and alcohol, are haemolytic and produce urticaria; he found also that they do not contain formic acid and that immunity to their effects is not acquired. Nuttall (1918) dealing with the effects of salivary glands of Phthirus on human skin states that the bluish spots of the skin are especially marked after biting of adult lice, that they have nothing to do with the blue spots in the fat body of the lice and that they are probably derived from the exuded and altered blood of man.

The spiral organism found in the stomach of various carnivora has been investigated by several observers (see the references at the end of this paper). Such studies have been mainly directed to the morphology of the organism, its infectivity and the part it plays in producing a pathological condition. In the present paper I have been concerned rather with the physiological condition of its host as influencing the prevalence and location of the organism in different regions of the stomach. I was anxious further to ascertain if the organism affected the normal processes of digestion in the stomach either to the advantage or the disadvantage of the animal entertaining it.

The present year, 1923, has already witnessed the celebration of more than one scientific centenary. From divers parts of the world men have gathered together to do homage to Louis Pasteur, who was born just over 100 years ago; to Edward Jenner, who died just 100 years ago; and to Christopher Wren, who died just 200 years ago. But probably only a few of those who joined in these public thanksgivings recalled that 1923 is also notable, in the history of science, for another reason. Exactly two centuries have now passed since the death of the first and greatest of all “microbiologists”—Antony van Leeuwenhoek, Father of Protozoology and Bacteriology, the man who discovered those “microbes” now called protozoa,'bacteria, and yeasts, which the illustrious Pasteur studied to such good purpose, and with which he laid, in part, the foundations of his scientific reputation: and it is exactly 200 years also since the death of another precursor of Pasteur—his countryman Louis Joblot, whose name is now almost forgotten, though it deserves to be remembered by all protozoologists.

Certain facts are known concerning the correlation of the distribution of animal species and the hydrogen ion concentration of the soil and water. An attempt is made to apply them to the distribution of malarial fever, as illustrating insect borne disease, and to some of the numerous Trematode infections, afflicting man and other animals, in which snails act as intermediate hosts. The importance of measurements of hydrogen ion concentration (by the colorimetric method) by field workers on the distribution of animals is urged.

The writer wishes to acknowledge his indebtedness to Dr M. V. Lebour for the suggestion that snails may prove a suitable group for the study of the relation between the reaction of the habitat and animal distribution.

The parasitic worm fauna of domesticated animals in India has in the past been greatly neglected as a subject for research by zoologists working in that country. The increased interest in Helminthology during the last few years has been world-wide, and has led to greater attention being paid to Indian parasitic worms, such attention has, however, been largely devoted to the Roundworms, the Flatworms, with the exception of the Trematodes, receiving but scant attention.

Christian Gottfried Ehrenberg, one of the outstanding scientific figures of last century, was born on Easter Sunday, 19 April 1795, at Delitzsch. In this town—then in Saxony, but now in Prussia—his father, Johann Gottfried Ehrenberg, was a municipal official, who was thrice married; his second wife being the mother of Christian Gottfried, who was the eldest son. His mother's maiden name was Christiane Dorothea Becker, and she was the daughter of the innkeeper of “The Red Lion” in Delitzsch. The forefathers of these Saxon Ehrenbergs were mostly millers, and they appear to have been unrelated to the noble family of the same name.

The genus Diaphanocephalus was erected by Diesing in 1851 to contain certain species included in Rudolphi's Synopsis in the old genus Strongylus. The species in question were Strongylus galeatus Rud., 1819, re-named Diaphanocephalus strongyloides by Diesing, and subsequently indicated as the type-species of the genus; S. costatus; and possible S. viperae Rud., which Diesing listed as a species inquirenda. In deciding upon the necessity for the new genus Diesing seems to have been influenced largely by the characters of the head. His diagnosis shows that he considered the supporting rays of the buccal capsule to be four only in number, regarding two of these as divided each into two distinct processes. Molin (1861) gave an emended diagnosis of Diesing's genus and proposed the new genus Kalicephalus for certain other strongyle parasites in reptiles. It has already been pointed out (Baylis and Daubney) that the generic characters used by Molin are unreliable and that Railliet and Henry (1909) were justified in abolishing Kalicephalus in favour of the older genus, Diaphanocephalus. Recently, Skrjabin (1916) has given a diagnosis of the genus. Through the kindness of Dr H. A. Baylis the writer has been able to examine specimens in the collection of the British Museum (Natural History), and the Wellcome Bureau of Scientific Research. The material examined includes four specimens of the genus Diaphanocephalus.

Mr J. F. M. FLOYD was good enough to hand over to me for report some smears which he had made in British Guiana from the contents of Termite intestines. Prof. Silvestri, who was kind enough to examine some Termites taken from the same colony as those which furnished the material for the smears, identifies them as belonging to the species, Rhinotertnes nasutus Perthy, and it is probable that this is the host of the parasite described below.

[This paper is the final report on the Diptera collected by the Percy Sladen Trust Expedition under Professor J. Stanley Gardiner, F.R.S., in the Seychelles and other islands of the Western Indian Ocean in 1905 and 1908–9. Many reports on the insects collected have appeared in the special series of volumes devoted to that Expedition, Tr. Linn. Soc.London, ser. 2 (Zool.), xii–xviii (from 1907 onwards), but it has not been possible to include all the entomological contributions in that series. I am greatly indebted to the Editor of Parasitology for accepting the present work, which was offered for publication in this journal as it deals with a number of parasitic forms—Bombyliidae, Sarcophaginae, Tachininae, etc. A list of all the other reports on Diptera collected by this Expedition, with full references, is given in Ent. Monthly Mag., 58, 1922, p. 184.

In recent years the speciation of parasites as related to their host relationships has presented some of the most interesting and at the same time most difficult problems in the field of parasitology. These problems are by no means of purely academic interest but are of prime importance in connection with the control and prophylaxis of a number of important infections of man and domestic animals.

During the year April 1921–April 1922 I examined the stools of 1034 men from the dysentery ward of the District Hospital, Kuala Lumpur, in the Federated Malay States. In this hospital the patients are for the most part indigent Chinese and Tamils of the coolie class, who have resided in Malaya for a length of time varying from a few weeks to a number of years, sometimes all their lives. From the way in which these people live, from the intimate mixture of so many different nationalities, and from their often extensive migrations, one might be led to expect that their intestinal fauna would be abundant both in variety of species and in incidence of infection. This expectation is not realised in the following results. Indeed, the figures for some of the non-pathogenic protozoa are not as high as some which have been obtained for healthy Englishmen who have never left England (cf. Matthews and Malins Smith, 1919). Nearly all the patients in this series were suffering, or had recently suffered, from active dysentery at the time when the examinations were made: and in some cases the flushing out of the intestine from this cause probably reduced the intestinal protozoa to such small numbers that none could be found when specimens of the stools were examined. In many cases, also, protozoa have certainly been overlooked in the masses of pus and other cells present in a very large proportion of the stools examined. Had it been possible to examine a series of cases without intestinal derangements involving diarrhoea from the same population, some opinion might have been formed as to the actual effect of these two factors on the results obtained. And until some such figures are available for comparison it cannot be said that the scarcity of some of the intestinal protozoa found in these cases has any special significance.

The hosts of the new Schizogregarine herein described are the larvae of Dolichopodid flies: Syslenus adpropinquans Loew and S. scholtzii Loew which live in the decomposed sap or wood-pulp filling the wounds of Elm and Horsechestnut trees. The larvae used for the present study have been obtained from two trees only: an Elm tree standing on the Caius College playing ground at Newnham and a Horse-chestnut tree standing on the Downing site. The new parasite Schizocystis legeri n.sp., in company with a gregarine Dendrorhynchus systeni Keilin (1920), often completely fills the lumen of the host's midgut, but, even when heavily parasitised, the host does not show any sign of infection. The latter can only be detected when the larvae, slightly pressed between a slide and a coverslip, are examined under the microscope.

In rabbits maintained for experimental purposes at this Department, there has been collected from the stomach on a number of occasions a nematode showing certain affinities with the genus Graphidium Railliet and Henry, 1909. The parasite in question, however, differs from the type species of that genus in characters which must be regarded of more than specific value and it has therefore been assigned to a new genus. It has only recently been noticed in our rabbits. I am indebted to Dr Smith for calling my attention to it. Whether the parasite had heretofore been overlooked in autopsy examinations or has been recently introduced cannot be said. It seems probable that it originated from a wild host and is indigenous to this continent. It was first noticed after our rabbits had been transferred to quarters where they had access to the ground.

Geoffrey Watkins Smith, M.C., M.A. (OxoN.) was born 9 Dec. 1881 at Ivy Bank, Beckenham, Kent and was killed on the Somme, in July, 1916, at the early age of 34. He was Fellow and Tutor of New College and Lecturer in the Department of Zoology and Comparative Anatomy at Oxford. His published work covers a period of only eleven years but it is remarkable in quantity and quality alike and shows forth its author as one who would have achieved the foremost rank among English biologists.