1. To determine the upper limit of the abomasal worm infestation of healthy lambs was the main object of the investigation. The results show that a lamb slaughtered fat before or shortly after weaning and therefore presumably a healthy lamb, may contain up to 2,100 Haemonchus and up to 4,670 Ostertagia.

2. Infestation with Haemonchus conlortus is negligible until August.

3. Infestation with Ostertagia remains almost steady from early May until mid-September.

4. Infestation with Trichostrongylus axei occurs from May until mid-September, but is never a heavy one.

5. The evidence suggests, but does not prove, that in mid-summer there is a wide difference in the infestation of single and twin lambs.

6. The results, so far as they affect the seasonality of infestation are, strictly speaking, applicable only to the flock of the Duthie Experimental Stock Farm, but are probably true for the North-East area of Scotland.

Dunnifilaria dilli, a new species of filariid from Rattus koratensis from Thailand is described. Adult worms were recovered from the lymphatic system. They differ from D. ramachandrani in their location in the host, the tail length, the shape of the spicules, and in the number of caudal papillae. Microfilariae are much smaller and unsheathed. Additional hosts include R. rattus and R. sabanus.

1. Echinuria leiperi n.sp. and Echinuria singhi n.sp. are described from aquatic birds. A key to the species of the genus Echinuria is provided.

2. Skrjabinoclava alii n.sp. is described from Threskiornis melanocephalus.

3. Synhimantus hyderabadensis n.sp. and Synhimantus suraiyae n.sp. are described from Centropus sinensis and Urocissa flavirostris, respectively. Their relationship with the rest of the species of the genus is discussed. Synhimantus invaginatus (Linstow, 1901) Skrjabin, 1924, is reported for the first time from India and is redescribed.

4. Aliella anhingae gen. et sp. nov. is described from Anhinga melanogaster and is compared with the related genera of the family Acuariidae.

1. The structure of the head in four samples of the genus Allodapa from Madagascar birds is described and shown to represent stages in the functional deformation of the pharyngeal portions.

2. All the specimens are considered to belong to Allodapa suctoria (Molin, 1860) s.l. and are described. Their hosts are: Margaroperdix sp. Centropus toulou, Coua caerulea and C. raynandii.

3. The species of the family Subuluridae known from Madagascar hosts are discussed and it is shown that they represent a minor parasite fauna which has most probably been secondarily introduced.

4. It is reported that Subulura prosimiae Baer, 1935 is indistinguishable from Primasubulura distans (Rudolphi, 1819) and that the record of the former species given by Chabaud and Petter (1958), based only on females, is that of a Subulura species and not a Primasubulura.

5. A Subulura species is reported from Coua gigas.

1. The infective stage larvae of Bunostomum trigonocephalum (Rudolphi, 1808) penetrate the intact skin and undergo skin-lung migration in the mouse and skin-lung-intestine migration in the guineapig. After percutaneous infection in guineapigs, they moult in the lungs to the fourth stage and to the fifth stage in the intestine. Relatively few of them undergo this partial development in the guineapig and they are stunted in growth.

2. In the abnormal hosts, the penetrating larvae cause extensive tissue disorganisation. The histopathology of the skin and lungs is described. There is a cellular reaction to the parasites.

3. In guineapigs, the infective stage larvae reach the lungs after per os infection but they are few in number do no persist for more than six days.

1. Chabertiella pesteri gen. and sp. nov. from the giraffe (Giraffe camelopardalis) is described.

2. Chabertia rishati Akhtar, 1937 is synonymized with Chabertia ovina (Gmelin, 1790) Railliet and Henry, 1909.

In the routine examination of stray dogs in a country area near Shanghai, a large percentage were found to be infected with Dirofilaria immitis. The microfilariae were easily found in blood films stained with Leishman's or Giemsa's stain. In some cases only a moderately heavy infection was found, but in some hyper-infection was present. (See fig.)

One male and four females were recovered from the anterior part of the intestine of the house rat, Rattus rattus kijabius in Kenya. They were found to belong to an undescribed species of trichostrongyloid for which the name Longistriata (Brevispiculoides) kenyae is proposed. I wish to thank my friend Mr. W. F. J. McClelland for the material, and Professor J. J. C. Buckley for his interest in the work.

Protective immunity against Brugia pahangi was examined after adoptive transfer of immune spleen cells. Spleen cells obtained from gerbils at 8 weeks post-infection (p.i.) with 100 infective larvae (L3) of B. pahangi were transferred into naive recipients, and then 24 h later, they were infected with 100 L3 of B. pahangi. The recipients given normal spleen cells and infected by the same manner served as controls. Microfilarial counts in the circulation were monitored at designated times after infection and worm burden and the size of individual female worm were determined at 16 weeks p.i. to evaluate the effects of adoptive immunization. In addition, eosinophil responses and serum antibody titres were examined during the course of infection. In the control group, microfilariae first appeared in circulation at 9 weeks p.i. and continuously increased in number throughout the course examined. In contrast, microfilaraemia was almost completely suppressed in the group given immune spleen cells. Although worm burden was comparable between the two groups, the average size of female adult worms recovered from the adoptively immunized group was significantlysmaller than that from the control group. Eosinophil response was hastened and enhanced by adoptive transfer of immune spleen cells in the early stage of infection. Parasite- specific antibody response was also hastened by adoptive immunization. These results suggest that immune spleen cells could confer protective immunity mainly directed against adult B. pahangi.

Third-stage larvae of Angiostrongylus costaricensis were cultured to young adult stages in Waymouth's chemically defined medium MB 752/l, which comprises higher concentrations of the essential components histidine, lysine, methionine, tryptophan, choline chloride and glucose than various other chemically defined media. The present study has shown that choline chloride and tryptophan are required at relatively higher concentrations for worm development than those of the other essential components.

In order to determine whether Taenia solium can be maintained in the laboratory using rodents as definitive hosts, six nude rats, 20 immunosuppressed Mongolian gerbils and 20 immunosuppressed Syrian hamsters were each inoculated through a stomach tube with three cysticerci recovered from SCID mice. No adult worms of T. solium were found in the intestinal tract of any of these 46 rodents. In addition, five immunosuppressed Syrian hamsters were fed with the same number of cysticerci enclosed in rodent muscles from SCID mice. Two of these hamsters were found to be infected 40 days post-infection, each harbouring a sexually developed worm in the intestinal tract. Although no eggs were produced, prepatent infections may be possible if a longer time was allowed for worm development. Moreover, the maintenance of the life cycle of T. solium in the laboratory using the rodent model can be established.

Experimental infections of pre-adult Galba truncatula (two populations) using one, two, three or five miracidia of Fasciola hepatica per snail were carried out to determine the total number of cercariae produced by snails when they were sacrificed at day 70 post-exposure (at 24°C). When the number of miracidia used for each snail increased at exposure, significant numerical augmentations of live rediae and of intraredial differentiating cercariae were noted. In contrast, only insignificant differences between mean numbers of free cercariae were found. The number of metacercariae produced by each snail (after shedding and/or after dissection) increased in infections with up to three miracidia per snail in each population and strongly decreased in infections with five miracidia per snail. Compared to the other types of infections, the delay of cercarial differentiation noted in the five-miracidia groups was probably due to the volume of the snail host, which would be too small to assure the complete development of five sporocysts.

100 male T.O. strain laboratory mice were divided into 4 equal groups: (I) 25 were injected intramuscularly with an antigen prepared together with Freund's adjuvant; (II) 25 injected with antigen alone; (III) 25 infected subcutaneously with 8 live plerocercoids of the same species; (IV) 25 served as controls. 4 weeks later all mice were given 6 live plerocercoids orally. The presence of acquired immunity in group III was shown by a significant reduction in the numbers, size and motility of challenge worms. The host response was greater in all the immunized groups than in the controls.

For the first time a Habronematid parasite (subfamily Habronematinae) has been recorded from a fish host. The parasite has been assigned to a new species of Cyrnea (Procyrnea).

During the examination of the eelworms assembled after washing pieces of turf by Thorne’s sieving technique (Goodey, T., 1949), which had been collected in a meadow at Winches Farm, St. Albans, several specimens of nematodes were found, both male and female, which were first identified as Tylenchorhynchus dubius (see Thorne, 1949). On closer examination of the male tail the spicules were seen not to be the proper shape. Further examination made it clear that a different species was being looked at which had several unique features, the most characteristic being the pattern of the cuticle. This, in addition to having well-defined transverse striae, had longitudinal markings such that the whole surface was divided into minute squares and gave the appearance of very delicate and exceedingly regular quilting. It is accordingly described as a new species with the name Tylenchorhynchus tessellatus.

During the course of an experiment on marine fish cultivation conducted from 1942-44 in Loch Craiglin, Argyllshire, some attention was paid to the feeding of fish as deduced from gut analyses. Most of the fish examined were flatfish and some account of their feeding has already been given (Raymont, 1947). A few round fish were also taken from time to time and a small number of these were gutted for food content.

Taenia solium cysticercosis is a major public health problem in developing countries. Swine cysticercosis results in economic losses for pig farmers in disease endemic areas. Consumption of cysticercotic pork leads to taeniasis in humans. Eggs excreted in the faeces of T. solium carriers disseminate to humans and pigs through the faecal–oral route, thus maintaining the life cycle in endemic areas. An enzyme-linked immunoelectrotransfer blot (EITB) assay was developed using whole crude T. solium cysticercus antigens (WCA) for the diagnosis of swine cysticercosis. Sera from 30 swine with cysticercosis confirmed by magnetic resonance imaging were subjected to EITB assay. Sera from 50 swine that were raised in a government farm and not allowed to roam freely were included as negative controls. Two or more bands of 8, 11, 14, 24, 26 and 29 kDa were immunoreactive on blot with sera from all infected swine except two, and none from swine raised on the government farm. The overall sensitivity and specificity of EITB assay for diagnosis of swine cysticercosis were 93.3% and 100%, respectively. Hence, EITB assay based on WCA may be a suitable diagnostic tool for swine cysticercosis in endemic areas.

Urban rodents are associated with parasites and pathogens, which present health risks for humans, but information on factors related to parasite and pathogen infection in rodents in cities of Latin America is scarce. This study analyzes the hosts, host community structure and environmental characteristics of parasite and pathogen fauna present in the three species of urban rodents in an urban area of South America. Rodents were captured seasonally in seven different neighborhoods. Digestive tracts were dissected under stereoscopic microscopy and feces were processed using a sedimentation technique. Protozoa and bacteria were detected through polymerase chain reaction and indirect immunofluorescence techniques. In Rattus norvegicus, Rattus rattus and Mus musculus, ten helminths, three protozoa and two bacteria were found. Six were zoonotic: Toxoplasma gondii; Hymenolepis diminuta; Rodentolepis nana; Strobilocercus fasciolaris; Leptospira borgpetersenii; and Leptospira interrogans. The parasite and pathogen infections were influenced by the host species, the host community structure, the season, and the presence of streams in the neighborhood. Urban rodents may be the infection source of many zoonotic diseases and it is important to generate public policies for this problem. This study is one example of the situation of many cities of Latin America, where peripheral neighborhoods are growing dramatically.

Kapsulotaenia tidswelli is a proteocephalidean cestode that utilizes varanid lizards as definitive hosts. Fresh specimens of this cestode were observed with endogenous red pigmentation in the neck region that disappeared rapidly if specimens were not preserved in glutaraldehyde. The ultrastructural characteristics of the red pigment, which are described, suggest it is a carotenoid. Phylogenetic analysis confirmed a close relationship between K. tidswelli and other species of Kapsulotaenia for which sequence information is available. There is thus no reason to consider that the red pigmentation is because K. tidswelli is atypical, and it is proposed the carotenoids are likely to be associated with the diet of its varanid host.