An account is given of the coprophilic habits of the holotrichous ciliate, Balantiophorus minutus Schew., and of the effect upon it of urine.

Experiments are described in which attempts were made to grow the ciliate in a wide range of human faeces of varying consistency and from both normal and diseased subjects. Abundant growth was obtained in normal faeces, both before and after dilution; but no growth took place in the undiluted faeces of softer or liquid consistency from various cases of intestinal disorder, even dilution frequently failing to render these a suitable medium. Moreover, the ciliate could not be recovered from such abnormal faeces by subculturing.

This behaviour was due to two primary factors:

(1) the high osmotic pressure obtaining in liquid stools which causes plasmolysis of the ciliates, and (2) the presence in the stools of unaltered bile salts, owing to the rapid passage of material through the intestinal tract. It was demonstrated that bile salts, even in very low concentrations, are highly toxic to B. minutus. Two secondary factors probably also serve to limit growth, namely, the presence of drugs with a toxic or depressing effect on the ciliate, and the presence of urine, which is not only highly lethal but also mixes more readily with a liquid than with a normal stool.

It was shown that the lethal action of urine upon the ciliate was due primarily to osmotic pressure, and, to a lesser degree, to the toxic effect of ammonia sometimes present in the urine. It was demonstrated that a concentration of urine as low as 5% inhibited multiplication in ordinary cultures, while as little as 1% prevented growth when admixed with normal faeces. It was further shown that urea has a depressing effect upon the reproduction of B. minutus. Paramecium caudatum was shown to be also susceptible to the lethal effect of urine.

Investigation of the effect of hypertonic solutions has shown that the limiting osmotic pressure which B. minutus can withstand for a prolonged period is represented by a solution of non-electrolyte with a depression of the freezing-point of about 0·60° C., or by a solution of an electrolyte with a depression of the freezing-point of 1·2° C. (represented by 1·9% sodium chloride solution) which is equivalent to about 6000 mm. Hg (8 atmospheres). It was also shown that osmotic pressure is not the principal limiting factor to the growth of the ciliates in such stools. The ability of other ciliates to live in hypertonic solutions is discussed and the conclusion is reached that B. minutus is more resistant than is usual among freshwater forms.

Experiments carried out on mice established that the cysts were incapable of passing through the mammalian alimentary tract and developing in the faeces after passage, so proving that B. minutus is an exogenous coprozoon.

It is concluded that (i) only polysaprobic Protozoa capable of movements in a viscous medium can lead an existence in undiluted faeces; (ii) under natural conditions urine probably acts as a limiting factor to the development of coprozoic ciliates in faeces; (iii) coprozoic Protozoa are derived from the soil fauna and have in turn largely contributed to the sewage fauna.

Simultaneous hermaphrodites maximize their fitness by optimizing their investment into male or female functions. Allocation of resources to male function (tissues, traits, and/or behaviours increasing paternity) is predicted to increase as density, and the associated level of sperm competition, increases. We tested whether the simultaneous hermaphroditic cestode Schistocephalus solidus uses cues of potential partner densities in its fish intermediate host to improve its male reproductive success in the final host. We had two worms, one originating from a multiple infection in the fish intermediate host and one from a single infection, sequentially compete to fertilize the eggs of a third worm. The fertilization rates of the two competitors nearly always differed from the 50–50 null expectation, sometimes considerably, implying there was a ‘winner’ in each experimental competition. However, we did not find a significant effect of density in the fish host (single vs multiple) or mating order on paternity. Additional work will be needed to identify the traits and environmental conditions that explain the high variance in male reproductive success observed in this experiment.

The following new species of Ixodes from eastern Africa are described and figured: I. rotundatus, I. auriculaelongae, I. nchisiensis, I. latus, I. loveridgei, I. spinae, and I. euplecti.

The female of I. oldi is redescribed and the hitherto unknown male and nymph are described and figured. Some consideration is given to two specimens from Uganda which differ in certain particulars from typical specimens from East and West Africa.

Cutaneous leishmaniasis (CL) is one of the most disregarded tropical neglected disease with the occurrence of self-limiting ulcers and triggering mucosal damage and stigmatizing scars, leading to huge public health problems and social negative impacts. Pentavalent antimonials are the first-line drug for CL treatment for over 70 years and present several drawbacks in terms of safety and efficacy. Thus, there is an urgent need to search for non-invasive, non-toxic and potent drug candidates for CL. In this sense, we have implemented a shape-based virtual screening approach and identified a set of 32 hit compounds. In vitro phenotypic screenings were conducted using these hit compounds to check their potential leishmanicidal effect towards Leishmania amazonensis (L. amazonensis). Two (Cp1 and Cp2) out of the 32 compounds revealed promising antiparasitic activities, exhibiting considerable potency against intracellular amastigotes present in peritoneal macrophages (IC50 values of 9.35 and 7.25 μm, respectively). Also, a sterile cidality profile was reached at 20 μm after 48 h of incubation, besides a reasonable selectivity (≈8), quite similarly to pentamidine, a diamidine still in use clinically for leishmaniasis. Cp1 with an oxazolo[4,5-b]pyridine scaffold and Cp2 with benzimidazole scaffold could be developed by lead optimization studies to enhance their leishmanicidal potency.

Of the two specimens of the little grebe, Podiceps ruficollis Vroeg shot in the environs of district Pilibhit, U.P., one harboured two mature specimens of the genus Schistotaenia Cohn, 1900 and a large number of specimens of the genus Tatria Kowalewski, 1904. Study of these specimens has shown that the former is a new species. So far as the author is aware, this is the first record of amabilid cestodes from India.

The nervous system of the female of Thelastoma bulhõesi is described. Three granular lobed structures, presumably arcade cells, are present at the anterior end of the female and of the male.

Corynetoxins, the toxic glycolipids produced by Corynebacterium rathayi colonizing bacterial galls induced by the seed gall nematode Anguina agrostis in annual ryegrass (Loliurn rigidum), did not affect embryogenesis or larval development of A. agrostis although they did inhibit the rate of egg hatching. Corynetoxins were not toxic to several species of nematode which are parasites of roots nor to various stages of the free-living nematode Caenorhabditis elegana and they did not appear to influence the numbers of C. rathayi that became attached to the surface of the cuticle of infective larvae of A. agrostis.

Mr C., who has lived for ten years in the tropics, was under the care of Dr de Jong and myself for chronic amoebic dysentery. Some five years ago he suffered from an abscess of the liver, readily cured after operation. Before this abscess he had never noticed any dysenteric symptoms, but afterwards he often had mild, or sometimes more severe, attacks of recurring dysentery, most times without fever. During the attacks, the bloody slime contained a great number of amoebae, principally of Entamoeba histolytica and containing erythrocytes. With an “emetine cure” the attacks regularly subsided; but between two attacks the patient produced constantly a great quantity of so-called “minuta forms” and 4-nucleate (“tetragena”) cysts of this species in the faeculent parts of the stools. After an emetine treatment I often found a rather sudden increase in the number of cysts (always measuring from 11·5–13·5μ), sometimes to a tremendous amount. Several times we tried to get rid of the amoebae by a cure with emetine bismuthous iodide, but without success, so the patient stayed under observation and regularly sent us his stools for control.

The object of the present investigation was a more complete description of the structure, and the elucidation of the life cycle, of Cercaria mehrai Faruqui, 1930, which was found to infect about 50% of snails, Indoplanorbis exustus, in the Allahabad district during the months of July to December.

The experiments here described make provision for some of the eventualities not covered by the previous experiments of Taylor and Purchase, and appear to give a more definite answer to the question on the effect of the presence of parasitic worms in aiding the entry of bacteria into the body.

Although the conditions, in these experiments, appear to have been very favourable for the bacteria present in the lumen of the bowel to invade the host through abrasions of the wall caused by the parasitic worms, the evidence of assistance given by the worms to the entry of bacteria has not been obtained. In view of these findings, and taking into consideration other experimental results, it seems highly probable that the injuries caused to the bowel wall by parasitic worms in general do not play any important part in bringing about bacterial infection from the lumen of the intestine.

The object of the enquiry reported on below was to determine, if possible, the method of infection of Lucilia caesar, L. with Herpetomonas luciliae, a common parasite of the alimentary tract of the fly, the subject being not too remote from the kalaazar problem to lack interest.

Early in 1925 I received from Mr E. Jacobson a mite taken in 1918 from the Passalid beetle Gnaphalocnemis (Eriocnemis) burmeisteri Kaup. on the east coast of Sumatra. It clearly belonged to the genus Megisthanus, and was apparently new. I had described and figured it before I showed it to Mr Stanley Hirst of the British Museum (Natural History), South Kensington. He informed me that he had received both sexes of what he believed to be the same mite, and most kindly offered to hand over to me the material to complete my account of the new species. By the courtesy of Sir Sidney Harmer he was permitted to do this, and I have therefore been able to examine, as regards external features, four female and three male specimens.

The genera Citellinema and Warrenius were established by Hall in 1916 with regard to specimens collected from alcoholic host material supplied by Mr E. R. Warren. The genus Citellinema was founded upon a single male specimen from Citellus elegans, named by Hall Citellinema bifurcatum, in reference to the bifurcated spicules. The genus Warrenius was based upon two males, one headless, from Eutamias quadrivittatus, to which Hall gave the name Warrenius quadrivittatus.

In bovine theileriosis the use of chemotherapy to control an infection sufficiently long to permit the establishment of a solid protective immune response has been developed as a routine vaccination procedure. Infections with Theileria parva and T. annulata can be prevented by the administration of carefully controlled numbers of sporozoites simultaneously with a long acting tetracycline and this form of immunization has been widely used for the control of East Coast fever in Africa with considerable success. In this review, the nature of the chemotherapy, the immune response and the interactions between chemotherapy and immunity in the development of infection-and-treatment immunization procedures are discussed.

1. Pure-line breeding of Calliphora erythrocephala is difficult owing to the fact that gravïd females will oviposit at a distance from decomposing meat and the newly hatched larvae will crawl long distances and pass through minute openings to reach the food.

2. A simple and convenient cage for breeding blow-flies is described.

3. To obtain eggs free from contamination meat is plunged in boiling water before being put in the cages; and the vessel in which it is placed is sup ported on a glass cylinder standing in a dish of water.

4. The larvae are fed on horse-meat placed upon sawdust in a large watch-glass resting upon sawdust in a bowl. The bowl rests upon a support surrounded by water.

5. Pupation occurs in the sawdust beneath the watch-glass and puparia are separated from the sawdust by sieving.

6. Pupae are kept in glass dishes with closely fitting covers to prevent parasitism by Hymenoptera.

7. At a temperature of 21° C. the complete life cycle takes about 1 month.

Four specimens of this parasite were collected from the gills of about two dozen Dussumieria acuta, a fish which is of market value in Madras. Of the four specimens, two were female and two were male; no two were found in the same fish. Both the males were 1·5 mm. long, while the two females measured 2·6 and 2·5 mm. respectively.

In a collection of parasitic mites from Palestine sent by Prof. O. Theodor, Hebrew University, Jerusalem, the author found several larval mites which prove to be new species, one in the genus Euschöngastia the other two in the genus Trombicula. These are described and figured in the present paper along with a new species of the genus Blankaartia taken on a bird in Uganda and sent for identification by G. H. E. Hopkins, O.B.E. (formerly Senior Medical Entomologist, Kampala). The author wishes to acknowledge his thanks to the above donors for having given him the opportunity to examine these specimens.

Cases of myiasis by Hypoderma in a human subject in Great Britain are of sufficient rarity to warrant the recording of the following case.

A larva taken from a “small abscess on the neck of a boy aged 10”, was sent to the British Museum (Natural History) by Mr Colin Matheson of the National Museum of Wales, with a request that it be identified. The specimen was not in particularly good condition but after examination it was determined as a fully grown first stage larva of Hypoderma bovis de G. (the “second stage” larva of MacDougall (1930), “third stage” of Laake (1921), “first stage” of Knipling (1935)).