1. Anopheles amictus in North Queensland is a favourable intermediate host for Wuchereria bancrofti, comparable but perhaps not quite equal to Culex fatigans. The two described varieties of A. amictus were both tested.

2. Experiments with Aëdes vigilax and Culex sitiens show that the former is a rather poor host and the latter a very poor one though infective larvae develop in some mosquitoes.

3. In experiments with Aëdes argenteus none of the sixty-two mosquitoes used proved hospitable.

4. Some observations on the transmission of filariasis in New Britain and on mosquitoes there are mentioned.

1. Experiments on the liberation of cercariae from their snail hosts have shown that under normal conditions C. limbifera (Seifert) and Cercaria “Z” n.sp. emerge during the day-time only, while in C. cambrensis I (Wright) the emergence takes place during the whole twenty-four hours, but considerably more so during the night-time.

Continual darkness causes a decrease in the numbers emerging, and a lowering of the temperature partially or completely checks the escape of the larvae.

In Cercaria “Z” there is a double maximum between 11 a.m. and 4 p.m. in the numbers liberated.

The invasion of L. truncatula by the larval stages of Fasciola hepatica leads to the disintegration of the host's tissues, the appearance of black pigment and the reduction of the liver cells to a thin layer of protoplasm containing the nuclei.

The entry of blood pigment into the tracheal system after a large meal, previously described in Glossina, has been shown to be an artefact of fixation.

It is perhaps well known that the males of the genus Phlebotomus are purely “sexual forms,” i.e. their main function in life being to fertilise the females; they die after having copulated. In laboratory-bred strains of argentipes, it was found that the females were sought by freshly emerged males. I have observed that when a male approaches a female he sways his slender abdomen to and fro laterally and when close to her an unerring lateral swing of his abdomen links the two horizontally through the agency of the male terminalia. The couple remain in this horizontal position facing oppositely with the wings of the male placed ventrally to those of the female for about a minute, after which the insects separate. In several instances a couple in conjunction was seen to move or make short flights in a direction at right angles to their line of linkage.

Le nombre des espèces d'Hémiptères, hématophages, entomophages ou phytophages, attaquant l'homme, habituellement ou occasionnellement, est assez considérable (voir en particulier E. de Bergevin, Les Hémiptères suceurs de sang, Archives de l'Institut Pasteur d'Algérie, 3, 28–44, 1925, et J. G. Myers, Facultative blood-sucking in phytophagous Hemiptera, Parasitology, 21, 472–80, 1929). A Ia liste déjà longue qui a été établie il convient d'ajouter la Nabis apterus Fabr. (= Nabis lativentris Bohemann) qui jusqu'à présent avait été considéré comme inoffensif pour l'espèce humaine. Or l'année dernière, au mois de septembre, dans une petite localité du canton de Berne (Suisse), un individu de cette espéce est venu se poser pendant Ia nuit sur le cou d'une personne et lui a implanté son rostre dans la peau, cela, non pas pour se défendre, mais, semble-t-il, pour se repaître du sang de sa victime. La piqûre a provoqué une douleur assez violente, analogue à celle d'une guêpe, qui a été suivie de prurit et d'une légère intumescence de la peau. Les effets de la piqûre, probablement atténués par l'application d'ammoniaque, ne se sont fait sentir que quelques heures.

The new species herein described was found in three species of monkey at the Moscow Zoopark, the animals having been imported via Germany.

An account is given of the life cycle and morphology of T. grayi in the crocodile (Crocodilus niloticus) and in the tsetse-fly (Glossina palpalis). The immunological relations of this trypanosome to its hosts and its affinities to other species are also dealt with.

T. grayi belongs to the group of trypanosomes developing in the posteriorstation of the invertebrate host and transmitted by the contaminative method (“lewisi group”).

T. grayi occurs in very small numbers in the crocodile and is concentrated chiefly in the peripheral circulation of the skin (about 200 parasites per 1 c.c. of blood). It is one of the largest trypanosomes, the blood forms measuring up to 91μ

When fed on an infected crocodile the tsetse-fiy takes up not more than about six trypanosomes. These commence their development in the mid-gut, giving rise to crithidial and trypanosome forms, and later extend to the hind-gut where their evolution is completed and the infective metacyclic trypanosomes are produced. These, when voided with the faeces, serve to infect the crocodile per os.

Since the incubation period of T. grayi in the crocodile is about four days, this is the time required for the small metacyclic trypanosomes to develop into the large blood forms.

The distribution of T. grayi in the gut of the fly in the course of its development is determined by the presence of the peritrophic membrane and involves three successive waves of migration in opposite directions: (1) From the intraperitrophic space backwards, into the colon, thence (2) forwards into the extraperitrophic space up to and including the mid-gut; and finally (3) they again migrate backwards, to the hind-gut. (Diagrams of the life cycle and distribution of T. grayi in Glossina are given in Text-figs. 2 and 3.)

Evidence is produced to show that the so-called “cysts” of T. grayi described by previour authors are really artifacts.

Apparently the majority of crocodiles in Victoria Nyanza harbour T. grayi. The trypanosome has no harmful efleet upon the crocodile and it was proved that the infection can persist for more than two years.

The crocodile appears to possess a natural partial or tolerance immunity against T. grayi, which does not protect it from invasion by the parasite, but maintains its numbers at a constantly low level.

The infection rate in the experimental tsetse-ffies is very high (average 61 per cent.) in the early days of infection, but later f ails to an average of 17·3 per cent. The majority of the flies, originally fully susceptible to infection, appear to acquire an immunity after the fifth day.

The average degree of infection in “wild” flies is 11·2 per cent. This compares closely with that in the experimental flies. Hence it is inferred that the majority of these flies had fed in nature on infected crocodiles.

T. grayi is closely allied to trypanosomes of the “lewisi group” and to some of the trypanosomes of land reptiles and amphibia. On the strength of the clifterence existing between these two groups of trypanosomes, some modification in the accepted classification of these species is introduced.

A name, T. theodori sp.n., is proposed for the goat trypanosome described by Theodor (1928).

During the early years of this century, several new species of ticks were described from Western Australia, but since then the group has been neglected, with the result that no species have been added since 1909. In the course of some recent studies of the local ticks, an undescribed species of the genus Ixodes was obtained, of which a description is now given.

In September, 1930, Dr E. C. Faust brought back from the Coto Region of Northern Panama two young female spider monkeys (Ateles geoffroyi). On December 11th one of these died from an experimental infection of Strongyloides stercoralis, and at autopsy was found to be very heavily infested with lice. Previous to this date the monkey had been handled a number of times but no lice noticed, although the two monkeys had frequently been observed carefully examining each other for external parasites. It is believed that the subsequent separation of the two (November 22nd) combined with the victim's illness allowed the lice to multiply at a prodigious rate. The hairs practically all over the body were found to bear nits, frequently as many as three or four per hair. Only a few lice have ever been found on the other monkey in spite of several careful examinations.

During recent years numerous forms of ectoparasitic trematodes have been discovered on the gills and body surface of fishes in Australia. Their descrip tions have been published in papers by Johnston and Tiegs (1922), Miss Kent Hughes (1928), and Johnston (1930). For the relevant literature on similar forms from other regions these papers may be referred to.

In 1917 Montgomery described a tick-borne gastro-enteritis of sheep and goats for which the name Nairobi sheep disease has passed into general use. In a comprehensive paper dealing with his work at Kabete he was able to show that the causal agent was a filtrable virus, transmitted by Rhipicephalus appendiculatus, the ordinary brown tick and common vector of East Coast fever in cattle. In spite of Montgomery's careful description of the lesions, of his record of failure to infect cattle, and of his successful filtration experiments, there has until recently been considerable confusion between this disease and heartwater, and opinions have been expressed that Montgomery was in all probability working with a strain of heartwater. During the course of certain investiga tions on heartwater the opportunity was taken to compare the two diseases and to confirm and extend Montgomery's observations.

[This paper deals with the biology of Pseudolynchia maura Bigot, the pupa and pupation period, sex ratio, offspring per female and longevity when bred under laboratory conditions by feeding on pigeons (the host in nature), chickens, mourning dove, man (hosts more or less unsuitable). Effects of the bite are described.—Ed.]

1. Some account of the occurrence of “Hepaticola” hepatica in various hosts is given, and it is recorded from the wood-mouse (Apodemus sylvaticus) in England.

2. Some additions and corrections are made to the morphological des scription of “H.” hepatica, which is shown to possess characters (presence of “bacillary bands,” presence of a spicule in the male) the supposed absence of which had led to the erection of the genus Hepaticola as distinct from Capillaria.

3. The status of the genera Hepaticola, Eucoleus, Thominx, Calodium and Liniscus is discussed, and the conclusion is reached that these should all be suppressed as synonyms of Capillaria, which is redefined.