Two new species of coccidia belonging to the genus Wenyonella are diagnosed here by the characters of their oocysts. Wenyonella uelensis and W. parva are geographically related (Uele, Belgian Congo) to the type species, W. africana Hoare (Uganda). By their hosts, two rodents of which one is a terrestrial squirrel, one can relate them to the second species, W. hoarei found in an Indian squirrel by Ray & Das Gupta. W. uelensis is sharply differentiated from the two previously known species, W. africana and W. hoarei, by its oval form, whilst W. parva is noticeably smaller.

The coccidium of mice (Mus musculus) was discovered by Eimer (1870) who named it Eimeria falciformis. It is round or oval. According to Reichenow the round oocysts measure 13·5–15μ and according to Reimer (1923) 14–18·9μ The oval oocysts measure 13–14×8–9μ or 16–21×11–17μ A residual body may, or may not, be present in the oocysts, but is present in the sporocysts. There is no polar granule in the oocyst.

1. The inhibitory effect of Ascaris extract on pepsin and trypsin is confirmed. This inhibition is shown not to occur with papain.

2. The inhibitory effect is shown to be brought about by a combination of the anti-enzyme with the enzyme and not by any of the other possible causes.

3. The extract is shown to have a proteolytic as well as an inhibitory action and these two properties are shown to be due to one and the same substance.

4. The term “ascarase” is suggested for this substance.

5. The ascarase is shown to be a readily diffusible substance of the order of a primary albumose, is precipitated by ammonium sulphate and 70% alcohol, is only slowly destroyed in acid but rapidly in alkali and is not digested by trypsin. It combines with the greatest quantities of substrate at pH 5–7.

6. Ascarase is found in the various tissues of the worm in the following order: ovary, oesophagus, gut, body fluid, ovojector, lateral line, uterus and cuticle. A similar order was found for the male.

7. The results found by de Wael (1933) for T. saginata do not apply to Ascaris.

8. The effect of the ascarase on the host and its function in the worm are discussed.

1. A progenetic metacercaria of Phyllodistomum lesteri sp.nov. is found encysted in the fresh-water shrimps, Palaemon asperulus von Marten and P. nipponensis de Haan.

2. A systematic description is made of this new species including general characteristics of the family, subfamily and genus and a list of the existing 29 phyllodistomes.

3. In general, the new form resembles Pleurogenes medians with regard to its progenetic development.

4. Feeding experiments suggest that two species of fish, Odontobutis obscura and Pelteobagrus fulvidraco, and a species of toad, Bufo bufo asiaticus, are not the final hosts of Phyllodistomum lesteri sp.nov.

The helminths dealt with in the present paper were recovered from an Indian chukar, Alectoris graeca chukar, brought in for examination by Major H. O. Pugh, D.S.O., Glandyfi, Cardiganshire, on 21 April 1938. The bird was one of several which were brought over from India in December 1937, and which were kept in captivity up to the date of examination of the bird under consideration. The death of this bird was found to be due to entero-hepatitis caused by Histomonas meleagris (Smith, 1895).

Protection against infection with Trichinella spiralis is conferred upon mice by the passive transfer to them of a specific immune serum from rabbits. A smaller percentage of mice treated with the immune serum die, and fewer larvae invade the muscles of the treated mice than among control animals. The action of the antibody of the immune serum appears to be directed specifically against the ingested larvae which are maturing to adult worms in the intestine of the infected animals. The results obtained thus far indicate that an immune serum would have little therapeutic value in the later stages of the disease.

An investigation was made of certain aspects of the physiology of nematodes from the alimentary canal of sheep.

Cellulose digestion has apparently no effect on the nematodes.

The composition and concentration of a physiological saline solution suitable for Ostertagia circumcincta—and possibly for the other species—was determined.

The effect of acidity on the intestinal worms showed that they could not live in the abomasum because the acidity in this chamber would be too great. O. circumcincta could not inhabit the stomach of horses, and carnivores, or the abomasum of cattle, in all of which the acidity reaches a level lethal to this species.

A graph is given showing the distribution of the nematodes in the small intestine of the sheep. After a study of the effect of bile salts on the different species its influence in determining this distribution is discussed.

A discussion of the evidence relating to the food of nematodes of the alimentary tract led to the conclusion that even species with rudimentary buccal capsules might suck blood; on the other hand, the results from the benzidine tests and spectroscopic examinations indicate that the haemoglobin demonstrated in nematodes is synthesized by them.

It was shown that O. circumcincta does not probably feed on abomasal contents. Bacterial difficulties hampering these experiments were overcome by using an apparatus whereby the contents of the abomasum could be percolated over the worms. The latter had been surface-sterilized with acriflavine solution.

All attempts to feed the nematodes on serum, defibrinated blood, and blood digests failed. Bacteria again constituted a difficulty, but it is suggested that the failure is not entirely due to them, and that perhaps the tissues of the host must be incorporated into the media.

The genus Pseudaspidodera was founded by Baylis & Daubney (1922). Recently I had an opportunity of examining a collection of worms of this genus from the gut of two Indian peafowls, Pavo cristatus. I am grateful to Mr K. K. Banerjee of the Bengal Veterinary College, Calcutta, for kindly placing the material at my disposal. Three species of the genus Pseudaspidodera have so far been described, viz. P. pavonis Baylis & Daubney (1922) from Pavo cristatus and Pavo muticus, and later from Argusianus argus; P. voluptuosa Chandler (1926) from Argusianus argus and Rollulus roulroul and P. spinosa Maplestone (1932) from Argusianus argus. The parasites under consideration cannot be assigned to any of the species referred to above. The separation of the cephalic cordons in P. pavonis, the presence of spines along the cephalic cordons in P. spinosa, and the longer left spicule in P. voluptuosa are sufficient to distinguish these worms from my specimens. I take this opportunity of recording my sincere thanks to Dr Baini Prashad and Mr M. N. Datta of the Zoological Survey of India for giving me facilities for examining the type specimens of P. pavonis and P. voluptuosa. I am indebted also to Prof. P. A. Maplestone of the School of Tropical Medicine and Hygiene, Calcutta, for kindly lending me the co-types of P. spinosa. The species has been named after one of my colleagues, Mr Jnanendra Lal Bhaduri, M.Sc., who has helped me with many helpful suggestions.

1. The so-called parasitic dinoflagellate occurring in the gut of the polychaete worm Scolelepis fuliginosa Clpde. is described and is shown to be the sexual phase of the gregarine “Selenidium foliatum” Ray.

2. The gametocytes (often very unequal) associate by their posterior ends while in situ. One remains attached and its epimerite is transformed into a foot-like organ serving to attach the gametocyst to the host throughout the rest of development. The gametocyst is elongate and pyriform (26−226 × 9−34 μ) and its formation involves very little alteration in the shape of the gametocytes. Solitary encystment also occurs.

3. The first gametocytic nuclear division is described. Forerunners of the gamete nuclei are formed within the nuclear area of the gametocyte. Flagellated isogametes are formed. There is no residuum.

4. The spores are spherical, averaging 8·5μ in diameter, the number depending on the size of the cyst enveloping them. When ripe, they contain four or eight spindle-shaped sporozoites 9·4−14 × 2−3·75μ and, in vivo, a central, spherical, refrigent residuum.

5. A new genus Selenocystis is proposed for this organism, with S. foliata (Ray) as the type species. Although I have not found its asexual phase, the probability is that it may still be classified among the schizogregarines.

Eupelmella vesicularis Retz. was found in certain parts of Hungary infesting cocoons of Diprion sertifer Geoff. already parasitized by a primary parasite, Microplectron fuscipennis Zett. It was never found in the absence of this chalcid.

Experiments showed that Eupelmella confined itself almost exclusively to Microplectron as a host, easily detecting the presence of larvae or pupae of this parasite within the cocoons of the saw-fly host, but neglecting eggs.

A single egg is laid per cocoon and the larval Eupelmella eats from 10 to 20 Microplectron larvae or pupae, and finally kills all the remaining living parasites within the cocoon before pupating.

The egg and larva show interesting structural adaptations for this mode of life.

Reproduction is parthenogenetic and no males are known.

Several factors combine to make this insect a dangerous enemy of Microplectron capable of seriously impairing its efficiency. These are: its selective ability, its destructive powers, its rapid rate of increase due to the parthenogenetic habit, and its ability to establish itself and survive on small numbers of the prey, for the same reason.

Amongst the collections of mites that have been sent to me for identification I have recently found six new species which are described and figured in the present paper.

The parasites described in this paper were taken from twelve specimens of the Natal horseshoe bat (Rhinolophus geoffroyi zuluensis) found in a cave near Wartburg, Natal, in May 1937. Thirteen specimens of the parasite were taken from the vibrissae situated on or near the nose-leaf of the host, each of them being attached near the base of one of these tactile hairs. No single vibrissa was found to have more than one parasite attached to it. The largest number of mites taken from any one host animal was four, the smallest was one, and none were found on any part of the body other than the facial region. With the aid of a hand lens the parasites can easily be seen clinging to the nasal vibrissae, where they appear as minute white specks. So far as I am aware mites of the family Listrophoridae have not previously been described or recorded from South Africa.

About a year ago when examining the intestinal contents of various fresh-water fishes of Bengal, I obtained a new acanthocephalan parasite, Acanthosentis dattai, from the small intestine of Barbus ticto and B. stigma. In a single host as many as twenty were obtained, but the average number of parasites taken from other hosts was four to ten. Some of these were found lying in a sluggish state in the lumen of the intestine. About the months of July and August some were found in copula.

Numerous specimens of this fluke were collected in October 1936 from the small intestine of the Bonell's eagle, Hieraetus fasciatus fasciatus, shot in the vicinity of Allahabad. Only one out of six hosts examined was infected. The sexually mature worms, 1·171–2·622 mm. long, are distinctly divided into elliptical forebody and cylindrical somewhat posteriorly pointed hindbody. The forebody, 0·969–1·236×1·186–1·476 mm., with foliate lateral margins united behind the holdfast Organ, is armed with very minute, backwardly directed spines; the hindbody is 1·2–1·386×0·634–0·818 mm. The length ratio of fore and hind parts is approximately 6:7.

In Part I the musculature of the internal organs of the male blow-fly, C. erythrocephala, testis, vas efferens, accessory gland, vas deferens, and ejaculatory sac and duct, is described, together with the movements observed in them and the passage of secretions down the system. It is suggested that the testicular and accessory gland secretions are ejaculated separately. The musculature, mechanics and co-ordinated movements of the external organs and associated structures are also described.

In Part II the generative organs of the female, except the ovaries, with special reference to their musculature and movements, and the musculature of the ovipositor are described and compared with those of M. domestica. It is suggested that the male accessory gland secretion is kept separate from the testicular secretion, the former passing into the lateral sacs of the female and the latter into the spermathecae.

In Part III the relation of the parts of the two sexes during coitus is discussed.

1. Three species of flea were found on rats caught on the docks of Plymouth, England, namely, Nosopsyllus (Ceratophyllus) fasciatus, Xenopsylla cheopis, and Leptopsylla segnis (musculi).

2. The findings of Xenopsylla cheopis were almost entirely confined to a certain grain store, whence the flea was obtained constantly throughout the period of the investigation.

3. A few rats caught in the town of Plymouth yielded Leptopsylla segnis and Nosopsyllus fasciatus, but no Xenopsylla cheopis.

1. T. axei eggs in sheep faeces hatch at a temperature of 38° C. and a relative atmospheric humidity of 29%, but all of the larvae are dead 96 hr. after the initiation of the exposure. Eggs kept in faeces at −7° C. are killed within 96 hr.

2. Eggs do not hatch while under water but remain viable for 20 days under 15 mm. of water at temperatures ranging from 11 to 28° C. Under natural conditions the longevity would in all probability be influenced by such factors as depth of water, amount of decomposing organic debris, etc., which determine the amount of available oxygen present.

3. Completely embryonated eggs in sheep faeces possess a high resistance to drying. It is apparent that ranges and pastures in California cannot be freed of eggs by keeping suitable hosts off them during a single dry season, because the eggs can survive desiccation for a period exceeding the dry season. It is possible, however, that if the eggs were directly exposed to the rays of the sun they might be killed.

4. The non-infective larvae of T. axei are very much less resistant to desiccation than are the eggs. The population of non-infective larvae would, however, under the more common natural conditions, normally attain the infective stage before succumbing to desiccation.

5. Infective larvae lived for more than 104 days at a temperature of 38° C. and a relative atmospheric humidity of 29%. At −7° C. they were alive at the end of 25 days but were dead on the thirty-ninth day. It is believed that under natural conditions such larvae would not be exterminated by high temperatures. At low temperatures the usual covering of snow might sufficiently protective to prevent death.

6. T. axei infective larvae survived 230 days' submergence in 5 mm. of water at room temperature in diffused daylight. Direct sunlight appears have some lethal effect. The amount of oxygen available in the water appears to determine to a considerable degree the longevity of the larvae. Under natural conditions infective larvae can survive even greatly prolonged flooding.

7. The survival of infective larvae to desiccation is dependent upon the actual degree of dryness attained. Larvae dried on glass slides at room temperature ranging from 17 to 27° C. with a relative atmospheric humidity of from 35 to 51% survived up to 16 days after the initiation of exposure.

8. Different investigators have obtained different results in studying the longevity of infective larvae in soil. The writers believe that the infective larvae do not spend much time on soil or migrate through it unless to escape some unfavourable environmental factor such as particularly high or low temperatures or desiccation, or unless they are accidentally washed into it during heavy rainfall.

9. No evidence of phototropic behaviour was observed. It is believed that vertical migration up vegetation is caused by a negatively geotropic reaction which may be conditioned or altered at times by stronger external stimuli resulting from extreme temperatures, bright sunlight, low atmospheric humidity, etc.

10. It is believed that the seasonal incidence of trichostrongylosis on irrigated ladino clover pastures in California is determined by acquired resistance, age resistance, or both.

11. A mixture of a 1% solution of 40% nicotine sulphate and 1% copper sulphate appears to be a more efficient anthelmintic against T. axei than a straight 1% copper sulphate solution. Changing from green feed to hay or rendering hay available along with green feed may possibly have a therapeutic effect. Spontaneous recovery, so far as clinical symptoms are concerned, from an acute trichostrongylosis, without the administration of a drug or changing the diet, seems to be common, if not the rule, in the majority of lambs in an infected band.

References to dipterous parasites of Diptera are rare in the literature. Bombyliids of the genera Villa and Thyridanthrax have been reared from the puparia of Glossina; Hemipenthes morio L., from the tachinid Parasetigena segregata Rond., and the sarcophagid Sarcophaga affinis Fall.; Argyramoeba varia F. from the tachinid Sturmia inconspicua Mg. The phorid Hypocera incrassata Mg. was found by H. M. Morris in dead and unhealthy larvae of Bibio marci L. Only one larva of Hypocera was obtained from each specimen of Bibio, and the account given by Morris suggests that this species is a true parasite. The evidence is, however, not absolutely conclusive and further study of this interesting species is desirable. The same thing must be said of E. E. Edwards' record of Aphiochaeta brevicostalis Wood, as a parasite of Tipula sp.

This trematode was obtained from cockles brought up with mussels to the Conway Mussel Cleansing Station and also from cockles collected from several other localities on the Menai Straits. It was present in every cockle examined, a total of several thousand in all. It occurred as a brown mass of varying size situated immediately beneath the hinge and occupying a small wedge-shaped cavity which occurs there. It could be obtained by cutting away the hinge with a knife when the brown mass was exposed. The latter breaks up very easily on teasing and consists of numerous more or less oval thick-walled sporocysts loosely embedded in the tissue of the cockle. These sporocysts are colourless or slightly straw-coloured and immobile. They contain a varying number of cercariae and a considerable amount of granular brown material. The fully developed cercaria (Fig. 1) is transparent except for the excretory sacs, which are full of very highly refractive granules and appear dark. The maximum diameter of these granules has been put forward by Rothschild (1935) as a valuable diagnostic character; in this species it is 5μ. The cercariae are moderately active and survive some time in sea water after removal from the sporocyst. This trematode was found throughout the year.