1. The anatomy of the genitalia of Gigantocotyle bathycotylc is described.

2. An account is given of gametogenesis, egg-shell formation, and the first two cleavage divisions.

3. The chromosome number is given as n = 6, 2n = 12.

Two new species of Paramphtstomum from cattle are described, namely, P. hiberniae n.sp. and P. scotiae n.sp., first collected from Irish and Scottish cattle respectively.

A brief account of gametogenesis and early cleavage division is given.

The chromosome number for P. scotiae is n=8, 2n=16, for P. hiberniae no definite number is given but it is believed to be n = 8 (6–8), 2n=16 (12–16). Notes are made on some specimens received from the Netherlands and France.

P. hiberniae and P. scotiae are compared with P. cervi and P. leydeni.

From the study of the worm egg output of nearly fifteen hundred sheep on many hill farms in Scotland it has been shown that:-

(i) Worm egg output in ewes and gimmers is lowest in early winter and highest in spring and early summer; this is followed by a marked decrease towards the winter months.

(ii) Generally in ewe hoggs the worm egg output is the same as that in older sheep, but shows greater variability; on occasion the spring peak may be absent.

(iii) The level of worm egg output of hoggs is generally higher than that of older sheep, and in this respect gimmers tend to fall between hoggs and ewes.

(iv) Weather conditions may have an influence on the height and duration of the spring peak of worm egg production.

The value of the hanging-drop technique as used by Professor Buckley for the examination of the different views of the tip of tail and head of small nematodes is stressed. The spicules of various species of Enterobius have been examined with polarized light and the significance of the basal portion of the spicules is discussed.

E. vermicularis is recorded for the first time from the Chimpanzee(Anthropopithecus troglodytes), the Lar Gibbon of Malaya (Hylobates lar) and the Silky or Lion Marmoset (Leontocebus rosalia) all of which had been in the London Zoological Gardens for varying periods.

The hitherto unķnown male of E. anthropopitheci is described and the female is redescribed.

A new species, E. buckleyi from the Orang Utan(Pongo pygmaeus) is described.

A new species, E. lerouxi from the Gorilla(Gorilla gorilla) is described. This is the first record of an Enterobius from this host.

E. bipapillatus is described and recorded for the first time from the Guenon Monkey(Cercopithecus aethiops) from S. Rhodesia.

A new species, E. brevicauda is described from the Chacma Baboon(Papio porcarius) from S. Rhodesia. This is the first record of an Enterobius from this host.

Negative findings for Enterobius are recorded from ten postmortem examinations and fourteen NIH swab examinations of Rhesus Monkeys(Macaca mulata).

A new species, E. interlabiata is described from the Feline Douroucouli(Aotus felinus) from S. America. This is the first record of an Enterobius from this host.

In view of the criticism of Kreis (1932) the type and paratype material of E. atelis, E. lagothricis and E. duplicidens and some more recent collection of E. lagothricis have been re-examined and the findings of Cameron (1929) and Buckley (1981) confirmed.

A D-D mixture was tested against the Root-Knot Eelworm, Heterodera marioni (Cornu), in a glasshouse devoted to the growing of tomatoes under commercial conditions in South Wales. The effects of four different rates of application, namely, 0, 200, 300 and 400 lb. per acre injected at a depth of seven inches at staggered points fifteen inches apart were investigated.

Improvements in growth of the tomatoes and reductions in the eelworm manifestations on the roots were produced in proportion to the increases in the dosage rate. Height of the plants, number of flower trusses and yield of fruit were selected for actual measurements of the effects produced on the growth of the tomato plant. All of them showed a graduated response to the injections at 200, 800 and 400 lb. per acre, the yields of marketable tomatoes, for example, being at the three dosage levels, respectively, about 200, 850 and 450 per cent. higher than in the controls.

The nematocidal effects were measured independently by grading the roots into four distinct categories, according to the severity of the pathological manifestations associated with the presence of Heterodera marioni. Judging by the results obtained in this way, D-D reduced the infestation by something like 25, 50 and 75 per cent, when injected at the rate of 200, 800 and 400 lb. per acre respectively. No information regarding the quantity necessary to effect complete extermination is available but it seems that an application exceeding 400 lb. would be imperative for this purpose at least in heavily infected soils where 70 per cent, of the plants are liable to suffer severe infestations.

1. Heavy infestations of the coelom-dwelling trematode, Dictyocotyle coeliaca, in rays are reported.

2. Of seven species of skates and rays examined, 16 of 55 specimens of R. naevtis and 81 of 78 specimens of R. naevus and 31 of 73 specimems of R. radiata were infested.

3 The spindle-shaped, three-sided operculate eggs are described and possible modes of exit from the male and female hosts are discussed.

4. A number of immature stages have been found and descriptions are given. Unlike the adults, the opisthaptor projects prominently beyond the posterior margin of the body, but the number and arrangement of the loculi appears to be the same.

5. The systematic position of the trematode is discussed.

Tests have been made with methyl bromide to investigate its efficiency in destroying infective stages of some helminth and protozoan parasites of poultry and game birds. It appears to have an immediate strong lethal action against ova of the common nematode parasites and against oocysts of Eimeria tenella. Its efficiency against ova of Choanotaenia infundibulum was not definitely proved. When used in the field, it penetrates soil to a depth of several inches, and in so doing destroys both ova and many invertebrates known to be vectors of poultry parasites. Land which has been treated remained quite free from parasitic infection for many months but gradually became re-infested. Wild birds were probably the agents for they carry ova accidentally on their feet and in the gut.

A new member of the genus Trichostrongylus Looss, 1905, was collected by the writer from the gastric stomach (abomasum) and the duodenum of an old eland bull in 1981. The animal was shot at a spot amongst the Nega Nega Hills to the east of the Great North Motor Road in the Mazabuka Provincial District.

Eight males and twelve females were collected from the pyloric end of the abomasum which also harboured a large number of Haemonchus mitchelli LeRoux, 1929, and a few specimens of Ostertagia circumcincta (Stadelmann, 1894). Two more males and four females of the new species were encountered amongst a large number of Cooperia spp. including Cooperia neitzi, Mönnig, 1981.

Several specimens of a trichostrongylid, for which the name Paracooperia mazabukae sp. nov. is proposed, were collected from the duodenum of the Oribi (Ourebia ourebi), a small African antelope, in vicinity of the Nega Nega hills in the Mazabuka area, Northern Rhodesia.

Four species of Paracooperia Travassos, 1985, have hitherto been recorded from the small intestine of ruminants. Schwartz (1929) based his description of Cooperia nodulosa on specimens collected from nodules in the mucosa of the small intestine of a carabao (Bubalis bubalis) in the Philippine Islands. Mönnig (1981) described Cooperia serrata, since designated as the type of the genus Paracooperia Travassos, from the springbuck (Antidorcas marsupialis), not Damaliscus albifrons as recorded by Daubney (1988) who records Cooperia serrata Mönnig, 1931, as having been collected frequently from sheep in the Rift Valley and the Athi Plains in Kenya. Daubney notes that the normal host of this helminth has not yet been discovered in Kenya.

It is well known that certain weeds can act as alternative hosts for some races of stem eelworm, thereby tending to defeat the objects of crop rotation. During the course of advisory work in this province, collections of weeds have been made from various sites where stem eelworm attacks were known to have occurred, with a view to discovering which ones were likely to act as bridging hosts.

While it is fully realised that the presence of D. dipsaci in a weed growing amongst a crop infested with this eelworm does not prove that the eelworms are of the same biologic race, it is felt that observations of this kind are a valuable and necessary preliminary to host transference experiments.

1. Syngamus parvus Chapin, 1925, S. gracilis Chapin, 1925, and S. merulae Baylis, 1926, are shown to be synonyms of S. trachea (Montagu, 1811). These conclusions are important in judging the epidemiology of the species.

2. The list of hosts has been critically revised and supplemented with two new hosts, Melanocorypha calandra and Larus canus.

A technique is described for the floatation and enumeration of trematode eggs. A special sampling and mixing pipette has been designed. The floatation fluid is a solution of potassium mercuri-iodide (K2HgI4). A modified McMaster egg-count slide, or else a calibrated sliding toppiece apparatus is used for counting the eggs and estimating the number per gramme of faeces. The apparatus is illustrated and described.

Syngamus trachea is one of the more difficult parasitic worms to dislodge owing to its position in the trachea. Many contrivances such as twisted feathers and spirals of fine wire have been used for the mechanical removal of the worms. In the hands of experts, they may be reasonably effective, but much injury frequently follows their use by amateurs, and the damage is often severe enough to cause the death of the bird. Anthelmintics which may be administered in food and water are seldom excreted by the lungs or are excreted in such low concentration as to be ineffective. Garlic oil and salicylic acid have been used, but are only very slightly effective and cannot therefore be considered as satisfactory treatments. Many so-called gapeworm cures consist largely of substances which stimulate the respiratory musculature and induce a sudden explosive cough.

During the course of some anthelmintic tests carried out during June, 1949, it was necessary continuously to feed 4 per cent, phenothiazine to pheasant poults in the daily mash, which they ate without any obvious distaste and grew reasonably well. The birds were a mixture of several varieties of Phasianus colchicus, including some Formosan and Korean hybrids. These latter birds have a light coloured plumage and it was soon noticed that the feathers were darkening. The change was obvious less than 86 hours after the first experimental feeding. All the birds were therefore examined and it was found that all were similarly affected though it was less obvious among the melanistics and blacknecks, which have a darker plumage. The leg scales too had taken on a distinct dark green hue, and this became more intense as the tests proceeded; the pigmented feathers assumed a fiat brownish colour, while the filoplumes are distinctly red.

1. This paper presents experimental evidence to show that Limnaea truncatula is not the only British snail susceptible to infection with Fasciola hepatica.

2. Of the six British species of Limnaea, five may be infected under laboratory conditions, L. auricularia proving resistant to infection. Full development of the parasite occurs in L. truncatula, L. slagnalis, L. palustris and L. glabra, while development as far as the production of rediae occurred on one occasion in L. pereger. Of the susceptible species L. truncatula may be infected at any age or size, but the other species are susceptible only during the first few days after hatching.

3. F. hepatica appeared to be relatively pathogenic to hosts other than L. truncatula even though the level of infection (as evidenced by the number of rediae which developed) was considerably lower than in the more usual host.