The following is a report on a collection of four species of parasitic nematodes from some mammals of Kwangtung Province, South China.

A consideration of the therapeutic doses generally used by South African doctors who avoid toxic effects during the treatment of schistosomiasis indicates that a permanent cure of the disease may be effected with either the potassium salt or the sodium salt of antimony tartrate within a month. A dose of 2 grains need never be exceeded with antimonium potassium tartrate in fresh solution as a maximum repeated dose. A total of 20 grains of this salt is a sufficient total dose; but the solutions of the drug should not be kept. The sodium salt of antimony tartrate was found less stable than the potassium of this compound.

A survey of the relatively few anthomyid types described in this paper alone is sufficient to show that the external form of the egg may differ greatly from species to species. It would be interesting to find out if these differences are related in any way to the subsequent development or habits of the larvae.

The Diptera larvae can be divided from an ethnological point of view into four categories: and the members of each, though of diverse systematic affinities, possess in common certain structural characters, which Keilin (1912) considers to be adaptations to the manner of life. The categories are as follows: (i) Saprophagous larvae: those which feed on decayed vegetable matter or the excrement of herbivorous animals; these have a buccal armature similar to that of Calliphora or Lucilia: the ventral surface of the basilar piece is feebly chitinized and has a number of longitudinal ridges projecting into the lumen of the pharynx. (ii) Phytophagous larvae, which feed on living plants, as leafminers, root-miners, etc.: these have the bucco-pharyngeal armature more concentrated, the basilar piece more chitinized, with ridges feebly developed or absent, the mandibles modified as several toothed scrapers. (iii) Parasitic larvae: their buccal armature resembles that of parasitic Tachinidae. (iv) Parasitic larvae—carnivorous larvae: It is now known from the researches of Portchinsky (1910), and later of Keilin himself, that a good number of larvae found in excrement are not really coprophagous, but live on other larvae or other small animals found with them in the excrement. These carnivorous larvae attack their prey, perforating its skin, and sucking its contents. For instance, the larvae of Graphomyia maculata, found in liquefied decomposing vegetable matter, feed on larvae of Eristalis and pupa of Tipulidae, those of Calliophris riparia, found among moss, feed on small oligochaete worms and larvae and pupae of Psychodidae. These carnivorous larvae have certain characters in common. Thus the mandibles are sharp, piercing hooks and the basilar piece of the armature is very long, narrow and strongly chitinized and entirely without the internal longitudinal ridges.” (Scott, 1915.)

The results of the study on the digestion of Gastrophilus larvae may be summarized as follows:

(1) Pepsin-like enzymes are totally absent.

(2) The salivary glands secrete a proteolytic enzyme, which has no effect on the digestion of casein, gelatine and fibrin, but acts on milk alone.

(3) The midgut is capable of secreting amylolytic, proteolytic and lipolytic enzymes.

(4) The body fluid contains a strong reducing substance.

(5) The body fluid, as was shown by Khemnitz (1914), contains an amylolytic enzyme which is also capable of converting glycogen into glucose.

(6) Free glycogen and glucose circulate in the body fluid of the larva during the prepupal and possibly the pupal stage also.

(7) The larva of Gastrophilus does not feed on blood, but lives on the fluid material partly digested by its host in the stomach.

(8) For this reason the horses do not show any symptoms even when there is a heavy infestation.

In this second contribution to the study of parasitic copepods of fish from Ceylon eight species are described, four of which are new. The male of one species, namely that of Euryphorus nordmanni Milne-Edwards, is described for the first time. Of the three remaining species, Caligodes laciniatus Kröyer has only been recorded once (Heller, 1865) since it was originally described in 1863 and the comparison of Caligus alalongae Kröyer and C. tenax Heller makes it easier to identify the males of these two forms.

Some time ago I received for identification a microscopic preparation of parasites taken, on 11 March 1929, from a flying squirrel (Sciuropterus volans L.) in the neighbourhood of Agraz, Tartar Republic. The preparation mounted in Canada balsam contained one male and two females. Later I examined a rather large collection of flying squirrels in the Division of Mammals of the Zoological Institute of the Academy of Sciences of U.S.S.R. In one jar containing a flying squirrel from Verchoijansk, Yakutia, 67° 33′ N, 133° 51′ E, I found, among the debris on the bottom, a single specimen of the same parasite.

A number of trematode parasites were taken from the digestive tract of a red-bellied watersnake, Farancia abacura (Holbrook), on 27 March 1933. This snake had been captured on the previous day from a canal at Harvey, Louisiana. The parasites were studied while still alive and were tentatively identified before being fixed with formalin while under the pressure of a cover-slip. Representatives of three genera were encountered. Two of the species, representing two separate genera, are considered by us to be new to science and are herein described under the proposed names of Cercorchis auridistomi n.sp. and Stomatrema guberleti n.sp. The third species was recognized as Vitellotrema fusipora Guberlet, 1928.

1. The Protozoa from the hindgut of the wood-feeding roaches Panesthia javanica and P. spadica are described.

2. These Protozoa are to be regarded as commensals.

3. They belong to three subphyla of the phylum Protozoa.

4. Two are flagellates, Monocercomonoides panesthiae sp.nov. and Hexamita cryptocerci Cleveland.

5. Two species of Endamoeba are described, E. philippinensis sp.nov. and E. javanica sp.nov., the former small and a bacteria feeder, the latter large and xylophagous.

6. An unidentified amoeba was observed in one roach.

7. Nyctotherus uichancoi sp.nov. was found in the majority of Panesthia javanica and infrequently in P. spadica.

8. Nine species of heterotrichous ciliates (Clevelandia gen.nov. and Paraclevelandia gen.nov.) make up the family Clevelandiidae fam.nov.

9. This family is characterized by the posterior position of the mouth which may occur at the end of a projection, varying in length. It is closely related to the family Plagiotomidae, to which Nyctotherus belongs.

10. A well-integrated neuromotor system is described in the family Clevelandiidae, being practically identical in all members.

11. The relationships of Panesthia, Cryptocercus, the domestic cockroaches, and the termites are discussed on the basis of their protozoan faunas.

During the course of my investigation of the parasitic infection of various fishes of the Calcutta markets, I came across a new acanthocephalan parasite, Neoechinorhynchus topseyi, from the intestine of Polynemus heptadactylus, commonly known in Bengal as Topsey or mango-fish. The host was available in the local market during the months of February-August, and infection with this parasite marked during May-July. A single case was, however, noticed in August 1935 when after the intestine was taken out a portion of the threadlike parasite was seen hanging from its anal region. The intestine was slit open and it was found that one gravid female measuring 69 × 1· mm. was the only occupant of the entire lumen of the gut. The parasite was attached by means of its proboscis to the anterior part of the intestine near the duodenum.

During my stay at the Zoological Station of Wimereux, Pas de Calais, France, in August 1934, I made a special study of Protozoa parasitic in marine fishes. The examination of ten specimens of young Raia batis revealed a coccidial infection in two individuals, measuring about 25 cm. in length. In one of these the mucus in the terminal portion of the intestine contained a few unsegmented spherical oocysts, with diameters from 24 to 28μ. Sections of different portions of the intestine and of the liver failed to exhibit any stages of schizogony or gametogony, evidently owing to the fact that there was a single infection at the end-phase. However, the second skate showed very numerous unsegmented oocysts in the posterior portion of the alimentary canal (Pl. I, fig. 1). This specimen provided material for the morphological study and biological observations which follow.

Bassett-Smith (1898 a) described a new parasitic copepod from the gills of Cybium guttatum at Bombay and named it Helleria armata, but later (1898 b) altered the name of the genus to Cybicola as the former name happened to be preoccupied. This parasite was not again recorded until the present author (1935) redescribed the female from the gills of Scomberemorus commersoni (Lacepede) (= Cybium commersoni) and at the same time suggested the transference of this species to the genus Pseudocycnus Heller (1865). The reasons for this suggestion were based on a comparison of the female of Bassett-Smith's species with the females of the two known species of Pseudocycnus (vide Wilson, 1922). Now, however, the author has been able to obtain from the same host a male of this copepod which is here described. The evidence from this description concludes the argument in favour of the inclusion of this form within the genus Pseudocycnus.

1. The occurrence of Adelina cryptocerci in the host, Cryptocercus punctulatus, and its probable means of natural transmission are discussed.

2. Artificial infection experiments were carried out and furnished material for determination of succession of stages in the life cycle of the organism. The cycle is briefly as follows:

(a) Mature cysts are ingested by the hosts with tissues of infected roaches. Sporozoites enter the host's tissues by passing through the midgut wall.

(b) The first schizogony, in which merozoites are produced, ocurs in the fat-bodies between the sixteenth and twenty-fifth days after ingestion of cysts.

(c) In the second schizogonial generation two types of schizogony produce merozoites and gametoblasts, respectively, between the twenty-fifth and twenty-ninth days following infection. There is evidence that both male and female gametoblasts are formed from a single schizont.

(d) Male and female gametoblasts become associated during the growth period of the latter. When fully grown, they are surrounded by a membrane, the gametocyst. The male gametoblast undergoes 2 divisions, forming 4 microgametes, of which 1 fertilizes the macrogamete and the other 3 lie unused between the gametocyst and the first oocyst, which is formed shortly after fertilization. A second oocyst is formed before the first division of the synkaryon.

(e) By repeated divisions of the synkaryon a multinucleate sporont is formed. This divides into uninucleate sporoblasts. Each sporoblast divides once, forming a sporocyst containing 2 sporozoites. Mature cysts occurred in experimentally infected roaches from 40 days onwards.

3. The stages in the life cycle are described in detail.

4. Evidence for zygotic meiosis in Adelina cryptocerci is presented.

5. The effect of the parasite on the host is discussed.

This investigation has been made at the suggestion of Dr Harold Kirby, Jr., and under his direction and that of Dr C. A. Kofoid. I wish to express here my grateful appreciation to both for their interest and many valuable suggestions and criticisms.

Among the shore crabs the genus Callianassa is quite cosmopolitan; its species are widely distributed and seem also to be peculiarly susceptible to parasitism. Wherever they have been examined carefully they have yielded semi-parasitic copepods, sometimes in considerable numbers. Such forms have been reported from both the east and west coast of North America, from the Mediterranean and from the British Isles. Recently 150 of these semi-parasites were sent to the United States National Museum from Salaverry near Trujillo on the coast of northern Peru. They were taken by Mr Floyd Sears, agent of the Grace Line at Salaverry, from the branchial chamber of a species of Callianassa on the Peruvian coast. They prove to be new species belonging to two genera of cyclopid copepods and are here described and figured.

In this paper the history is given of the maintenance away from man of certain strains of T. rhodesiense originally isolated from man in Tanganyika Territory.

1. An account is given of a sporozoan parasite, hitherto known as Monocystis thalassemae Lankester, and its coccidian nature is demonstrated.

2. Schizogony and sporogony both occur in the eggs of Thalassema neptuni while these are in the genital pouches (nephridial sacs). Schizogony was observed on three occasions, and only the later stages were seen.

3. The full-grown sexual parasites are vermiform and immobile. The males are smaller than the females.

4. The microgametocyte, when it becomes spherical, gives rise to very numerous, elongate microgametes, similar to those of Aggregata.

5. Fertilization has not been observed. The oocystic membrane is only sometimes formed and is always inconspicuous.

6. At all stages where a chromosome count was possible, the number of chromosomes was seven. The reduction division is zygotic. No polymitotic figures were observed either in microgametogenesis or in sporogony.

7. Numerous sporocysts are produced. These may contain as many as twelve nuclei, and presumably give rise to at least twelve sporozoites. The formation of sporozoites has not been observed by us, but was noted by Lankester.

8. A new coccidian genus, Ovivora, is created for this organism, which now becomes Ovivora thalassemae (Lankester) and is relegated to the subfamily Aggregatinae in Hoare's classification.

1. Onchocerca is recorded for the first time from English-bred cattle.

2. A specific diagnosis of O. gutturosa is made, O. bovis being regarded as a synonym. It is suggested that Stiles's description of Filaria lienalis may have referred to this species.

3. The microfilariae occur in the skin of infected cows, and blood-sucking flies of the genus Simulium were found to be the vectors.

4. Complete development was observed in S. ornatum and partial development in S. erythrocephalum. S. ornatum appears to be a very efficient intermediate host, as over 40 per cent became infected.

5. Culicoides nubeculosus, the vector of Onchocerca cervicalis of horses, does not appear to carry the bovine Onchocerca.

In this, the last paper to be published from the Uganda Institute, after an account of the strain that forms its main subject, the origin of T. rhodesiense will be briefly discussed in the light of the investigations recorded in this series of papers and a few general observations will be made.

Habitat and record. I am much indebted to Miss Miriam Rothschild for kindly presenting me with a female specimen of a new cymothoid isopod taken from the mouth of a fish known locally as Boca-Chica, which, in the words of the collector, is “slightly larger than a herring, scaled, and with a sucker-like mouth”, probably a loricariid, from Rio Napo, Ecuador.

1. Systematic measurements of all hookworm-like eggs from time faeces of 336 patients in Mauritius led to the finding of 8 per cent Trichostrongyle, 0·9 per cent Ternidens deminutus, and 0·9 per cent Ancylostoma braziliense-like eggs.

2. This percentage of Trichostrongyle eggs includes one case from an inhabitant of the French colony, Réunion.

3. Hookworm eggs of a very small size, possibly Ancylostoma braziliense were found unassociated with the typical Necator americanus eggs, in the faeces of an inhabitant of Rodriguez; the adult worms appeared drug-resistant.

4. A partial eradication of the Trichostrongyles was obtained in one case, and an apparently complete eradication in another, of 6 patients treated with carbon tetrachloride.

5. The Trichostrongyles expelled by one of the patients were identified as Trichostrongylus axei (Cobbold, 1879) Railliet & Henry (1909).

6. No particular symptoms which could be ascribed to the action of the Trichostrongyles were observed in any of the affected patients.

7. Drugs administered orally to a patient passing Ternidens deminutus-like eggs failed to dislodge any of his worms.