Early this year (1932) we examined eight American raccoons (Procyon s. Notocyon lotor) whose faeces, according to Darling, contained Coccidia of our species.

Two distinct species have been ascribed to the genus Ityogonimus: I. lorum (Dujardin 1845) and I. talpae (Goeze 1782). The difference between these two species was pointed out by Dujardin in 1845. In the case of I. talpae the ventral sucker is about one-third the diameter of the oral sucker, and is situated behind the anterior termination of the yolk glands. In I. lorum the ventral sucker is larger than the oral and lies completely in front of the yolk glands. Dujardin named the former Distoma ocreatum and the latter I. lorum. Witenberg (1926), in further researches on the species, came to the conclusion that the first-named was identical with Distoma talpae of Goeze (1782), and as a result of his work there now exist two species of Ityogonimus occurring in the mole, namely I. talpae and I. lorum. The synonyms of I. talpae (Goeze 1782) between the dates of 1782 and 1910 are as follows: Distoma talpae (Goeze 1782), Cucullanus talpae Müller 1787, C. ocreatus Shrank 1873, Monostomum ocreatum Zeder 1800, Distoma ocreatum Duj. 1845, D. lorum Melnikow 1865, Dolichosomum lorum Looss 1900, Ityogonimus lorum Looss 1907, and I. lorum Gonder 1910.

1. An account is given of the development of strains of Trypanosom gambiense in Glossina tachinoides.

Complete development with infection of salivary glands and hypopharynx occupies from 12 to 40 days and upwards, according to the strain of trypanosome used and the temperature conditions during development.

2. It is shown that the first or intestinal phase of development is passed within the extra-peritrophic space and that the lumen or intra-peritrophic space of the gut is not involved.

3. The importance of the proventricular infection as an index of maturing infections is stressed, and it is shown that filamentar crithidia are always present in this organ in the later stages of infection when infection of salivary glands is taking place. It has been proved that these filamentar crithidia may constitute up to 20 per cent. of flagellates in the proventriculus and are partly responsible for the further migration to the salivary glands.

4. An account is given of the infectivity to G. tachinoides of twenty-six strains of T. gambiense from epidemic and endemic sleeping sickness areas in Northern Nigeria. None of the twenty-six was proved to be non-transmissible and twenty-five of the strains gave Total Infectivity Rates in the tsetse of from 0·9–10·5, the Cyclical Developmental Rates ranging from 0·6–9·8.

5. No evidence has been obtained that strains of T. gambiense from chronic cases of human trypanosomiasis in endemic areas are less transmissible by tsetse than strains originating in epidemic areas.

6. An account is given of experiments in which G. tachinoides infected with T. gambiense were exposed to 37° C. for varying lengths of time. The effect of high temperature during the infecting period is seen in a marked and constant increase in the proportion of tsetse infected. In the case of one strain a total infection rate of 77·8 per cent. was obtained with true cyclical development in 73·5 per cent. of the tsetse used.

7. It is suggested that the temperatures at which experimental tsetse are infected in the laboratory with T. gambiense are excessively low, and an investigation is to be made into the optimum climatic conditions for development of the trypanosome in the fly with a parallel attempt to correlate this with the climatic conditions under which wild tsetse become infected in nature.

The cercaria is liberated from an unbranched sporocyst by the birth-pore. It is spindle-shaped and possesses a bifid tail. It possesses two suckers, a long oesophagus and a forked gut. The excretory vesicle is Y-shaped with two furcal extensions from its stem. The cuticle is unarmed. There is no stylet or cystogenous organ.

There is no redia.

All stages in the development of the cercaria are found within the sporocyst.

A method is described by which individual bed-bugs, weighing only 5 mg., can be accurately weighed, and their rate of loss of weight measured during starvation.

Fasting bed-bugs were kept for various periods at five temperatures, ranging from 8° C. to 37° C., and at four humidities—0, 30, 60 and 90 per cent. relative humidity—at each temperature. Analysis after the experiments showed that the same amounts of food reserves were used up at each humidity for one temperature, and, as more water was evaporated from those kept in dry air than from those in moist, the proportion of dry matter rose most rapidly in dry air. Protein was the main food reserve used.

Although the rate of loss of water was greatest in dry air, the rate of loss was relatively greater in moist air when the saturation deficiencies are compared. It appears that the insects conserve their water in dry air, but their surface area being so great in comparison with their volume, they cannot prevent all evaporation. This evaporation is at a rate nearly proportional to the saturation deficiency of the air.

In moist air water appears to be evaporated freely. It is suggested that the spiracles are kept closed more in dry air and less in moist, which accounts for the fact that the rate of evaporation is proportionately greatest in moist air.

A comparison is made between the results obtained with Cimex and Rhodnius.

1. The paper describes an experimental study on the effect of atmospheric humidity upon Rhadnius. The work was carried out on fasting males of known age, kept at 23° C. at different relative humidities; the proportion of water was determined after the lapse of definite periods of time. The normal male contains 30 per cent. of dry matter.

2. Taking the results after 42 days' starvation, at 30, 60 and 90 per cent. humidity, the weight of each group of bugs has fallen to 50 per cent. of what it was at the start of the experiment. Those kept in damp air have lost dry matter and water in the same proportion, so that the percentage of dry matter after starvation is still 30 per cent. of the total weight. Those kept in drier air lose more water but oxidise less dry material, so that the proportion of solids rises during starvation: in those kept at 30 per cent. relative humidity the proportion of solids rises to 39 per cent. The figures for insects kept at 0 per cent. humidity are consistent, but it is not possible to obtain them beyond the 32nd day.

3. Death is probably due to a rise in the concentration of the body fluid and not to the exhaustion of food material. This is shown by the fact that the exhaustion of solid matter is actually less in dry air than in moist, though mortality is only observed among the bugs kept in dry air.

The species of Oesophagostomum here described has been collected quite frequently from sheep and goats in certain parts of the colony, always accompanied by the commoner oesophagostome O. columbianum.

It has already been shown (Imms, 1930) that the stem generation of the frit-fly in the Harpenden district is subjected to natural destruction, to a marked degree, by the agency of certain hymenopterous parasites. Among these, two species, viz. the Cynipid Rhoptromeris eucera Htg. and the Chalcid Halticoptera fuscicornis (Walk.) were found to predominate in numbers. Parasitisation, to a lower degree, by the Proctotrypid Loxotropa tritoma Thoms. was also noted and the Chalcid Callitula bicolor Spin. was recorded for the first time as having been reared from this same host. Evidence was also brought forward which o appeared to indicate that the parasitisation of frit-fly by the above combination of species increases in intensity as the season advances. In other words the stem generation of frit-fly, attacking late sown oats, is subjected to markedly heavier parasitisation than when it attacks oat sown earlier in the same season.

The study of Aptinothrips rufus made in 1930, in the vicinity of Edinburgh, revealed the presence of a nematode parasite in the insect which seemed worthy of investigation. Little is known of the parasites of Thysanoptera in general, and I can find no record of any parasite of Aptinothrips.

In a previous paper (1927) I have given a general account of Dipterous larvae and their parasites living in the wounds of a horse-chestnut tree standing on the Downing site, Cambridge. This tree contained two types of wounds: (1) a surface wound with sap exudation or slime-flux, and (2) a large hollow or reservoir filled with water.

In a recent paper (Parasitology, 23, No. 4, 492) I described under the name Microcotyle sciaenae a new species of Microcotyle from the gills of Sciaena antarctica. Dr M. C. Hall, Chief of the Bureau of Animal Industry, Washington, D.C., has kindly pointed out to me that this name is preoccupied by M. sciaenae Goto (1894). I now propose the name M. sciaenicola in place of this homonym.

In 1927 Keilin described the fauna of a rot-hole and a slime-flux in a horse-chestnut tree (Aesculus hippocastanum) standing on the Downing site, Cambridge. For several consecutive years prior to 1927 he took there the larvae of the mosquito Orthopodomyia pulchripalpis Rondani (described as 0. albionensis by MacGregor), this being only the second record for Britain. In 1926 the chestnut tree was cut down and the part of the trunk containing the rot-hole was placed standing on the ground close to the Molteno Institute on its south side. As the rot-hole, after a time, ceased to be water-tight, its bottom was cemented and the “reservoir” kept filled with water. (For further details see Keilin in this issue, p. 280.) Three to four weeks later larvae of Orthopodomyia were found in the reservoir. It was not clear how this recolonisation had taken place as no other breeding place was known in the vicinity.

Oral and subcutaneous administration of the compounds aminopropyl-aminostyrylmethoxyquinoline trihydrochloride and o-β-diethylaminoethyl harmol hydrochloride causes the appearance of peculiar bodies in the blood cells of canaries and mice.

The bodies are irregular in shape and size, stain intensely blue with Leish-man's and Giemsa's stains, and are most numerous in erythrocytes, but occur also in eosinophiles, leucocytes and reticulo-endothelial cells.

The bodies show no cytological structure, are not seen to undergo multiplication, and are not transmissible by blood inoculation.

They are apparently non-living inclusions in the blood cells caused by the action of these two chemical compounds.