A technique is described for the recovery of strongyloid infective larvae from bulk pasture samples. Pasture sediment washed from herbage is first concentrated, and then larvae are separated by subjecting small portions of sediment to the influence of a slow vertical current of water in a specially-designed column. A more rapid flow of water into the separation apparatus at frequent intervals agitates the sediment and releases trapped larvae into the upward flow. Several sediments can be processed simultaneously using columns arranged in parallel. Larvae separated from sediments are counted by a KI flotation technique.

The specimens used for this study were obtained from two collections of helminths sent to the Commonwealth Institute of Helminthology for identification. The first was made by Dr. R. Sachs in his survey of parasitic infestation of wild herbivores in the Serengeti region, Tanzania and the second by Dr. L. D. Fay in a veterinary survey of game animals in Kenya.

In the present goat-dog material great individual variation was observed in the rostellar hooks. The strobila had either 3 or 4 segments in the gravid worms. The position of the genital pore was near the middle in the mature segments and posterior to the middle in the gravid segments. There were more testes anterior (average 27) than posterior (average 18) to the genital pore but they usually extended even behind the vitellaria. The cirrus sac was either elongated or pear shaped. The ovary was bilobed and uterus sacculated.

The cuticle is transversely striated in the region of the head vesicle and shows some longitudinal striations about (0·10 apart. The configuration of the rudimentary mouth capsule and the other head structures are as in the other species of the genus. The length of the head vesicle is 0·082–0·102 and its maximum breadth 0·043–0·055 (Fig. 1.). The oesophagus is 0-371-0-520 long and 0·031–0·043 wide. The nerve ring is situated 0·293–0·313 from the anterior end and the excretory pore is located at the level of the end of the oesophagus or at a short distance in front of it.

Antigens prepared from adult worms and microfilariae of Loa loa were used for an assessment of the sensitivity and specificity in diagnosis of double immuno-diffusion in agar gel, haemagglutination and fluorescent antibody tests.

Both antigens formed a broad band which moved slowly towards the cathode on electrophoresis, and each antigen separated into two protein fractions when passed through Sephadex G-200.

Both precipitating and non-precipitating antibodies were detected in sera from Loa loa patients. The haemagglutination test and fluorescent antibody test were sensitive in detecting Loa loa antibodies and would be of diagnostic value, but the double diffusion test in agar-gel was insensitive and would have a limited value in loiasis diagnosis.

Part of the cestode fauna of ten hyraxes captured in Kenya was studied.

The species of hyrax were Procavia habessinica Hemprich and Ehrenberg and Heterohyrax syriacus Schreber.

One hundred and five cestodes were fixed, stained, mounted and examined. Descriptions of specimens, including measurements, are recorded in text and figures.

1. Experiments were carried out to investigate the rapidity and duration of hatching of S. mansoni ova under simulated field conditions, using B. glabrata to detect miracidia hatching from infested faeces.

2. Hatching times varied according to consistency of the stool. Hatching started at 4 hours and ended at 32 hours for blended stools; started within 24 hours and ended within 48 hours for soft stools; and started at 32 hours and ended at 128 hours for hard stools.

3. Survival of B. glabrata was poor in the blended-stool experiments, but excellent in the soft-stool and hard-stool experiments.

1. Two snail species (Physa marmorata and Drepanotrema surinamensis), guppies (Poecilia reticulata), and tadpoles (Bufo marinus) prevented in various degrees the infection of susceptible B. glabrata by miracidia of S. mansoni.

8. When the animal decoys were used in “pure” groups, the snails were more efficient in reducing the infection in B. glabrata than the guppies and the tadpoles.

3. When the animal decoys were used in “mixed” groups, the combination of P. marmorata and D. surinamensis was the most efficient group in reducing the infection in B. glabrata.

A survey of the helminths parasitising the gastro-intestinal tract of lambs in Northern Ireland is described. Twenty-four species were identified from the three hundred and seventy-two animals examined, which were drawn from abattoirs in different areas.

The major species found in the abomasum were Ostertagia circumcincta, 0. trifurcata, 0. pinnata and Trichosirongylus axei. Nematodints battus, N. filicollis, T. vitrinus and Cooperia curticei were the most prevalent species in the small intestine. Some observations are made on the relative incidence and role in the production of parasitic gastro-enteritis.

Four methods of infecting hamsters with S. mattheei and S. haematobium were compared. The ring method was found to be the most efficient and the cercariae of both species penetrated in 10—20 minutes.