Observations made by various workers over many years have indicated more or less clearly the probability that there is in this country a race of the stem eelworm, Anguillulina dipsaci, capable of attacking oats, field beans, onions, rhubarb, parsnips and certain common weeds. One of the earliest records bearing on this is that provided by Bos (1892) who cited information, supplied to him by Miss Ormerod, which showed that field beans might be seriously attacked by the parasite when grown after oats which had suffered from “tulip-root”. Many years later Johnson (1936a & 1940) reported failure of beans from eelworm attack following “tulip-root” oats in fields in Yorkshire and showed the significance of common chickweed and cleavers as reservoir hosts on which the parasite can live in the absence of susceptible farm crops. In another paper (1936) he showed that A, dipsaci associated with crown-root of rhubarb is interchangeable between rhubarb and oats in both of which it is capable of setting up disease symptoms. In his 1940 paper this investigator showed that A. dipsaci from rhubarb readily infests oats and common chickweed and also transfers to beans and, further, that the parasite from both oats and beans is infective to cleavers and common chickweed and back from both these weeds to oats and beans.

A specimen of Cysticercus tenuicollis is described, which contained many daughter cysts in various stages of development. One of these cysts was a well developed daughter cysticercus.

The daughter cysts at all stages of development, are lined internally by a distinct cuticle, and have no scolices. The daughter cysticercus, like the parent bladder, has an outer cuticle and a well developed scolex and receptacular appendage.

There is evidence for regarding the daughter cysticercus as having been formed from a daughter cyst by a process of evagination of the latter in such a way that the cuticle has come to lie on the outside, rather than by a process of vesiculation of a scolex.

The daughter cysts appear to be homologous with the brood-capsules of Echinococcus. They are not strictly homologous with daughter hydatids or daughter coenuri.

Methods are described whereby a factorial experiment was set up to test the effects on 40 potato plants, growing in 15 Kg. pots of soil, of the three factors: (S) steam sterilization of soil, (H) infection of soil with about three million eggs ard larvae of Heterodera rostochiensis per pot, and (D) injection of soil with 10 ml. of D-D per pot.

Data from the infected half of the pots were also used to test the effects of factors (S) and (D) on the eelworm population.

The data from 10 plant criteria yielded three statistics: the variance ratio (F), the coefficient of variability (V), and the Normal difference (t) corresponding to each factor and interaction. From an examination of these, the following two criteria are selected as, between them, displaying all the significant treatment effects of the experiment:

In February 1947, Mr. D. W. C. Northfield, M.S., F.R.C.S., of the Neuro-surgical Department of the London Hospital, removed by operation a small coenurus from the spinal cord of a 14-year-old girl of Gillingham, who had developed symptoms of paraplegia in December 1946. The girl, who has never lived outside Britain, is presumed to have become infected during a period of evacuation in Wales in 1943–45, where she had had contact with a dog. Professor J: J. C. Buckley, who secured the coenurus through the kind offices of Professor Dorothy Russell, has already made a brief report on it (Buckley, 1947) and has placed at my disposal the original material for detailed study and identification.

A factorial experiment involving the presence and absence of three factors: steam sterilization (S), infection with some three million eggs and larvae of Heterodera rostochiensis per pot (H), and injection of 10 ml. of D-D per pot (D), the factors applied in that order, was carried out to ascertain the effects on the growth of 40 potato plants in pots containing 15 Kg. of soil.

In the event, the D-D was lethal to the great, majority of eelworms, so that treatments labelled (hd) and (hsd) were effectively reduced to (d) and (sd). This fact greatly complicated the analysis, but nevertheless enabled certain conclusions to be drawn. The use of this factorial design may be criticised in the face of this antagonistic action between, two of the factors. Nevertheless, the effects of H and D acting together on the plants was a subject of interest; the real fault in design lay in using too high a concentration of D-D, or in not using a series of concentrations. The fact that the concentration used was too high emerged from the experiment and was not known beforehand.

The pathology of the infection in the trout of Poulaphouca Reservoir is described.

An annual mortality was found to occur in the trout during the summer months. This was caused by peritonitis which is attributed to plerocercoids becoming active as a result of the increase in temperature.

It is demonstrated that the infection in trout is probably of a secondary nature resulting from their feeding on sticklebacks primarily infected from the Copepod hosts.

Desmidocercella leiperi n.sp. from Ardeola grayii is described in detail and compared with other related species.

Two species of Oxyspirura are recorded from new hosts. Oxyspirura mansoni from Galloperdix spadicea and O. (Cramispirura) popowi from Copsychus saularis.

Two new species of Oxyspirura are described, O. (Cramispirura) indica n.sp. from Kittacincla malabarica and O. buccosulcata n.sp. from Temenuchus pagodartum.

In an earlier paper Goodey (1940) gave a detailed description of the morphology of three species of Anguillulina viz.: A. multicincta (Cobb) Goodey, A. erythrinae (Zimmermann) Goodey and A. robusta (de Man) Goodey. All three species are associated with plant roots: A. multicincta is a parasite of banana roots, A. erythrinae is parasitic on the roots of certain common grasses and cereals such as Agrostis stolonifera, Lolium perenne and oats (the writer has also found it on hop roots), A. robusta though associated with grass roots has not, to the writer's knowledge, been found within plant tissues. In the case of all three species phasmids were easily recognized on the female tails and were described and figured but they were not seen on the male tails and it was assumed that they were probably absent.

The nematodes described below are in the collection of the Department of Parasitology, London School of Hygiene and Tropical Medicine and I am much indebted to Dr. R. T. Leiper, C.M.G., F.R.S., who allowed me to examine them and who gave me considerable help and encouragement throughout the work.

The present paper consists of descriptions of an encysted developing stage of Asymmetricostrongylus dissimilis, and of four newz species, Globocephaloides trifidospicularis, Pharyngostrongylus longibursaris, Zoniolaimus cobbi and Labiostrongylus australis. With the exception of L. australis, which is doubtfully recorded from Python spilotus, all the species came from the alimentary canal of the Australian wallaby, Macropus rufogrisea fruticus.

Six new species of Spirurids are described from terrestrial vertebrates from various countries. They are Camallanus macabukae n.sp. and Procamallanus brevis n.sp. from bull-frogs in S. Africa, C. multilineatus n.sp. from Rana catesbiana in N. America, Tanqua gigantica n.sp. from Python reticulatus and Naja. hannah in E. Indies and S.E. Asia, respectively, Ancyracanthopsis madagascariensis n.sp. from Dryolimnas cuvieri in Madagascar, and Physaloptera singhi n.sp. from the monkey (?) in S. America. Three species inquirendae, Camallanus sp., Streptocara sp. and Physaloptera sp. are also described. Some new morphological features in Habronema mansioni and Physaloptera paradoxa are discussed and the female of Hartertia zuluensis is described for the first time.

A method is described by means of which trichostrongylid spicules are separated from the surrounding soft tissues and their examination made easier. NaOH and KOH are the most satisfactory substances for this purpose, though both substances eventually act on the chitin of the spicules themselves, causing distortion. The reaction takes place at a temperature of 37°C. with reasonable speed. Spicules of Ostertagia can also be freed satisfactorily by this method but those of Nematodirus are quickly affected by the alkali, with consequent distortion.

Davainea madagascariensis is a rather rare human parasite, there being less than a dozen cases on record. It was originally described from children in the Comoro Islands by Davaine in 1869 under the name Taenia madagascariensis and has since been recorded from a wider area stretching from Madagascar and the neighbouring islands through Siam to the Philippine Islands in the Pacific Ocean. Recently some cestode segments were sent to Dr. R. T. Leiper, C.M.G., F.R.S. They had been passed in the stool of a human patient in S.E. Africa. They have now been identified as gravid segments of Davainea madagascariensis and this would seem to be the first record of the species from the mainland of Africa.

Transverse fission of Cysticercus pisiformis begins in the liver and is usually completed there. It is brought about by one or two annular constrictions which. ultimately result in the complete fission of the original bladder-worm into two or three parts. The posterior segments thus formed are normally acephalic.

Histologically, fission involves an initial hypertrophy of the cuticle and subcuticula at the zone of constriction, followed by their degeneration and loss, and by the increase and consolidation into a slender cord of the muscle and parenchyma fibres. With the rupture of the cord and the sealing up of the broken ends, fission is complete.

The majority of the bladder-worms do not undergo fission, but the process is apparently spontaneous and quite normal for the species. Its cause is unknown, but it is thought to have a phylogenetic significance.

The gall-forming nematode, Anguillulina balsamophila (Thorne) Goodey has been described by Thorne (1926) who figures a photograph of a galled leaf of Balsamorhiza sagittata. Thorne gives a brief description of the superficial appearance of the galled leaves and mentions that the heavily infested plants are often very stunted. He recorded the parasite on three hosts, two species of Balsam-root, Balsamorhiza sagittata Nutt., B. macrophylla Nutt. and Mule-ear, Wyethia amplexicaulis Nutt. Later Steiner and Buhrer (1933) reported the parasite from the annual sunflower, Helianthus annuus L. collected and identified by W. D. Courtney. The detailed structure, however, of the gall has not so far been described and as suitable material was to hand, this paper is the result of some observations made on the gall structure.

The previous observations of the author and others on the development ot Cysticercus fasciolaris and C. pisiformis have been confirmed and amplified by experimental studies, and the developmental processes of the two forms are compared. While definite information has been obtained on the age of the various developmental stages, there is considerable variation due to the subtleties of the host-parasite relationship.

The study of the development of the rostellar hooks of taeniids has been extended by the use of differential staining, histochemical tests and polarized light, and new facts, such as the chemical and optical differences existing between cuticle and hooklets and between blade and base of hooks, have been brought to light.

Although outbreaks of trichinosis in Great Britain have been sporadic, the present investigation shows the incidence of Trichinella spiralis in man in Southern England to lie between 7.9% and 13.7%, the average incidence being 10.8%. The condition of the larvae, either free or in thin- or thick-walled cysts recovered by the “digest” technique, indicated that the infections were of varying ages, from recent to those of many years standing. In six cases there was definite evidence of the presence of both recent and old infections.

Acuaria anthuris, the type species of the genus Acuaria, is described in detail and A. scutata is considered to be synonymous with it.

Acuaria skrjabini from Passer domesticus has been described and compared with the original description. It is a new record for India and Hyderabad.

Acuaria kungi n.sp. from Saxicoloides fulicata is described and compared with related species.

Acuaria sp. is recorded from Pastor roseus.

A new species of Cheilospirura from Accipiter nisus is described and compared with related species.