1. Eubothrium crassum (Bloch) is re-described with additional information about the scolex and genitalia.

2. Specific differences between E. crassum and E. salvelini are commented upon and figured.

3. The second portion of the uterine duct lying between the central chamber of Mehlis's gland and the uterine sac is established as the “fertilization chamber”.

4. Polar bodies and maturation divisions are described and figured in definite relationships with the ovum as evidence of normal maturation in a cestode.

5. The position of the receptaculum seminis is determined and a new name, the “vagina sac”, is given to what was previously described as a receptaculum seminis. It is thought to serve for propulsion of male and female cells into the uterine duct.

The evolution of the life cycles of the members of the family Dipetalonematiidae Wehr, 1935 (Filarioidea) is considered in the light of existing knowledge of spirurid nematodes. The hypothesis that the life cycles of the dipetalonematids originated from life cycles similar to those of Draschia megastoma, Habronema muscae and H. microstoma is considered to be incorrect. Alternatively, it is pointed out that in the primitive subfamily Thelaziinae Baylis and Daubney, 1926 there are forms with typical spiruroid life cycles (Rhabdochona ovifilamenta), forms with life cycles approaching those of the dipetalonematids (Thelazia spp.), and forms with life cycles intermediate between these two (Oxyspirura spp.). It is suggested that intestinal species similar to Rhabdochona gave rise to the more specialized spiruroids and forms that left the gut (Oxyspirura, Thelazia) gave rise to the dipetalonematids.

The dipetalonematids are believed to have originated from nematodes resembling the species of Thelazia and having life cycles like those of T. rhodesii, T. skrjabini and T. gulosa. Some of these worms established themselves in subcutaneous tissues. Like Parafilaria multipapillosa, they released their eggs through a break in the skin of the definitive host, thus causing a skin lesion that attracted various haematophagous arthropods which finally became involved as intermediate hosts in the life cycle. Certain species like the members of Parafilaria and Stephanofilaria (?) came to rely upon intermediate hosts that were unable to break the skin of the definitive host (Musca) and cutaneous lesions became permanent features of their life cycles. Other species became dependent upon intermediate hosts that could puncture the skin (mosquitoes, simuliids etc.) and skin lesions became unnecessary to the life cycle. The larvae of these worms then began to spread into the tissues of the skin, as found in Stephanofilaria, Onchocerca, and some species of Dipetalonema, and the infective larvae developed the ability to penetrate into the wound made by the intermediate host and perhaps, in some cases, the intact skin. Ultimately the larvae of some species habitually entered, or were deposited into, the blood stream and the adult worms were then free to colonize the vertebrate body as their larvae would then be available to the intermediate host no matter where the latter fed on the body of the definitive host; this group of worms gave rise to the many members of the family Dipetalonematidae.

The family Filariidae Claus, 1883 is briefly reviewed in the light of the above hypothesis. It is pointed out that many species, e.g. Diplotriaeninae Skrjabin, 1916, live in the air sacs of reptiles and birds and probably have life cycles similar to that of Diplotriaenoides translucidus, i.e. the eggs pass through the lungs, up the trachea and out in the faeces. It is thought that these forms may represent a separate line of evolution from that which gave rise to the Dipetalonematidae. Certain genera (Lissonema, Aprocta), occurring in the orbits of birds, probably have life cycles like Thelazia or Oxyspirura. Many other genera occurring in superficial muscles and subcutaneous tissues (Squamofilaria, Ularofilaria, Tetracheilonema, Pelecitus, Monopetalonema) may release their eggs through some sort of skin lesion. Studies on these forms are urgently needed as the details of their life cycles may shed fresh light on the origins of the more specialized filarioids.

1. The rate of development of the larvae of M. capillaris is slowed down as the temperature is lowered; at 25°C. the infective stage is reached after 8 days; at 5°C. after 98 days.

2. The differences between “pre-infective” and “infective” larvae, as described by Gerichter (1948), have been confirmed.

3. Larvae at the “infective” stage can withstand artificial digestion, but “pre-infective” larvae are unable to do so.

4. The infective larvae can survive for long periods within the foot of the intermediate host.

5. Pre-infective larvae can survive for seven days after the death of the intermediate host; infective larvae can live for sixteen days.

6. Naturally-infected slugs were found throughout the greater part of the year. 13.5 per cent of the slugs collected were infected but in most instances only a few larvae were present in any one slug.

A number of helminths from a small bat from a cave in Northern Rhodesia were presented by Dr. P. L. leRoux to the author for study. The collection of consisted of about twenty specimens of one species of trematode, Prosthodendrium cordiforme; the rest were nematodes, namely, two males and three females of Molinostrongylus pseudornatus sp. nov., at least one species of filarial worm, one species of Capillaria and one or two species of trichostrongylid nematodes. Only the first two helminth species mentioned above were studied in detail. The others, for one reason or another, were inadequate for detailed study.

1. Observations on faecal pellets, herbage and soil, under natural climatic conditions, indicate that the larvae of M. capillaris survive for several months. The majority of the surviving larvae remain in the faecal pellets, and do not pass on to the herbage.

2. In the laboratory, larvae survived for many weeks in dry faeces, but the longevity was less in wet faeces. They survived better at a low temperature range of 3–6°C, than at higher temperatures.

3. They exhibit a considerable degree of resistance to desiccation; some survived for a maximum of fourteen days at a relative humidity of 75%.

4. Bright sunlight rapidly kills off the larvae.

5. They can survive at temperatures below freezing point. All of the larvae were alive after three days' continuous freezing, but none were alive after being frozen for twelve days.

In 1939 the sugar-beet nematode, Heterodera schachtii Schmidt, 1871, was found attacking the roots of sugar beets in the Blackwell district near Sarnia, Ontario. Studies were started in 1947 on the control and biology of this cyst-forming nematode, including the susceptibilities of various cultivated and weed plants to the nematode. Susceptibility was based on the presence or absence or degree of infestation of gravid white females on the roots.

The description of this species is made from two males and one female specimen. They were collected from the intestine of the Homa fish from the Kafue River, Mazabuka, Northern Rhodesia by Dr. P. L. leRoux.

A number of these specimens were available for study. They were collected from the stomach of Galago crassicaudatus agisymbanus (Coquerel) in Tanganyika Territory by Dr. W. H. R. Lumsden whom I wish to thank for the material.

These stout worms have a thick cuticle which is finely striated. The well-developed lateral lips are smooth, hemispherical, each possessing a large triangular external tooth and three smaller internal teeth. There are two prominent papillae towards the dorsal and ventral margins of each lip. The cervical cuticle forms a collar round the anterior end.

1. Ignavia venusta de Freitas is recorded from the kidneys of two Fish-eagles (Cuncuma vocifer) and a Goliath heron (Ardea goliath) from the Southern Sudan.

2. Ignavia is regarded as a valid genus and to it is transferred Allechinostomum renale Yeh, 1954.

3. Ignavia inops de Freitas (= Echinostomum sp.inq. Dietz, 1910) probably does not belong to the genus Ignavia or even to the subfamily Echinochasminae.

4. A new species of Renicola is described from the kidney of the Goliath heron and is named R. goliath.

5. The affinities of R. goliath are discussed and R. brantae McIntosh and Farr, 1952 is figured.

6. The significance of the occurrence of these two flukes in the Southern Sudan is discussed.

1. Eufilaria sergenti Seurat, 1921 is recorded from the areolar tissue of the legs and neck of the White-crested Jay-Thrush, Garrulax leucolophus from the Himalayas.

2. A new species of filarial worm Chandlerella braziliensis is described from the Green-billed Toucan from Brazil. It differs from other species of Chandlerella in the presence of small preanal papillae.

3. Chandlerella and Splendidofilaria which are considered as synonymous by some recent authors are considered to be valid genera by the present writer.

4. The genus Buckleyfilaria Singh, 1949 is shown to be a synonym of Pseudaprocta Shikhobalova, 1930, and the genotype becomes Pseudaprocta buckleyi (Singh, 1949) n.comb.

A method is described for the recovery of Oxyurid nematodes from faeces and ingesta of mice, by washing and sieving after the worms have been stained with iodine. It can be performed in one quarter of the time and is more efficient and less fatiguing than the method previously employed.

(1) Cercaria splendens Szdiat was found in a specimen of Planorbis vortex, caught in a ditch near Utrecht, the Netherlands.

(2) Its morphology and behaviour are briefly described and compared with the data given by previous authors.

(3) A feeding experiment with the stickleback, Gasterosteus pungitus, is described. The preliminary conclusion is drawn that Gasterosteus is not the final host but probably acts as a transport host for this species.

Two methods of setting up axenic cultures of several species of Rhabditinae are described. Both methods depend on the killing and superficial sterilisation of gravid females with a chemcal steriliising agent, and their transferance to an innocuous medium containing antibiotics. The young worms which hatch from the eggs contained in the dead female worms are then collected aseptically. In one method merthiolate is used as a sterilising agent and in the other hydrogen peroxide.

The effectiveness of both methods in freeing the young worms from contaminating micro-organisms has been evaluated by inoculating standard bacteriological culture media with the worms.

Starting with such young worms, bacteria-free cultures have been set up using media previously described by Dougherty and his coworkers for the cultivation of free-living nematodes.

The results obtained in the tests described above are summarized in the following table :—

Matricaria matricarioides (Less.) Porter, self-sown in one of the inoculated pots, is an addition to the known weed hosts of narcissus races of D. dipsaci and a new host record for the species.

Seinhorst (1952) has emphasized the need for caution in interpreting the results of host tests with D. dipsaci. Exposure to heavy infestations will often result in invasion and local necrosis of the tissues of plants which are not true hosts of the race concerned. Seedlings may easily be killed outright in this way. The present tests lead to similar conclusions as shown, for example, by the results obtained with red clover and oat seedlings. Even deposition of eggs in the tissues cannot be taken as evidence that the eelworms have established themselves. It is considered, however, that a plant may be regarded as a true host when it is clear that the eelworms are breeding freely in the tissues, i.e. when eelworms in all stages of development are present with numerous eggs, and when infestation is able to persist during the normal life of the plant. With bulbous plants, the establishment of an infestation in the new bulbs after the leaves and flowers had died down was taken as evidence that the plant was a true host. The typical effects of D. dipsaci on the tissues of its hosts, e.g. hypertrophy of parenchyma tissues, enlargement and loosening of the cells and dry, mealy rotting, are also useful criteria, but some of these effects may be produced occasionally after invasion of non-hosts, as was found in a few of the inoculated clover seedlings.

1. Sandonia sudanensis gen. et sp. nov. obtained from the intestine of the freshwater fishes Synodontis schall and Distochodus niloticus in the Nile is described and its affinities with the members of the subfamily Schizamphistominae are discussed.

2. Brevicaecum niloticum gen. et sp. nov. from the intestine of Citharinus citharus from the Nile is described and placed in the subfamily Kalitrematinae.

A new species Fibricola sarcophila, is described from Sarcophilus harrisii from Tasmania. The history of previous records of strigeid from marsupial hosts is outlined and their possible relationships discussed.

An inverse relationship has been demonstrated between egg counts and antibody titres. This relationship is also evident on a seasonal basis in the “spring rise”.

The “spring rise” is preceded by a decrease in the immune status of the sheep and is terminated by a self cure mechanism which establishes a period of protection.

The significance of these findings is discussed with regard to the onset and development of the “spring rise”.

1. The protozoa reported from animal-parasitic helminths are summarised in three tables, with a few comments on some of the more interesting forms.

2. The microsporidian found hyperparasitic in Moniezia expansa and M. benedeni of sheep in England, and Moniezia sp. from a buffalo calf in Pakistan has been found to be identical with Nosema helminthorum described by Moniez, 1887, Plistophora helminthophthora Labbé, 1899, and Nosema bischoffi, Weiser, 1951. The valid name for the organism is therefore Nosema helminthorum Moniez, 1887.

3. The macroscopic and microscopic changes in parasitized tapeworms have been described, and it is believed that the microsporidian is not pathogenic.

4. The host distribution and the geographical distribution of Nosetna helminthorum have been dealt with. This parasite has so far been reported from France, Germany, Yugoslavia, Great Britain and Pakistan, and it is likely that, it will eventually be reported from other countries in which Moniezia is present.

Brachylaemus dasyuri (Johnston, 1912) is recorded from Thylacis obesulus (Shaw & Nodder, 1797) from Queensland. It is redescribed and Brachylaemus simile (Johnston, 1912) is confirmed to be a synonym.

A review is made of the species of Brachylaemus recorded from American and Australian marsupials. It seems probable that they have arisen from a common ancestral type parasite in an ancestral marsupial.

Four species of adult cestodes and one larval form were recovered from Rattus assimilis (Gould, 1858) from Queensland. Hymenolepis diminuta Rudolphi, 1819; and the cysticercus of Taenia taeniae-formis (Batsch, 1786) are new host records for Australia; the same infestations with Raillietina (Raillietina) celebensis (Janicki, 1902) have also been recorded by Baer and Sandars (1956). Two new species, viz:—Choanotaenia ratticola and Hymenolepis australiensis are described.

The type specimens are lodged in the Queensland Museum, Brisbane. Cotype and other specimens studied are also lodged in the Queensland Museum and in the Institut de Zoologie, Université de Neuchâtel, Switzerland; the Department of Parasitology, London School of Hygiene and Tropical Medicine and in the British Museum (Natural History).