There are conspicuous differences in respect of hibernation among the mosquitoes; for certain species, such as Culex pipiens and Anopheles maculipennis, hibernate as adults, but others, for instance A. claviger (bifurcates), pass the winter as larvae. These differences have been the subject of many investigations and of much theoretical discussion; perusal of the literature suggests that we still lack a sufficient knowledge of the facts. It is known that an accumulation of fat in autumn is characteristic of those mosquitoes which hibernate as adults, as it is of several insects of other orders. But it seems that little is known of the quantity of fat stored, or of the rate at which it disappears as winter passes. It is my present purpose to set out certain observations on the composition of adult female Culex pipiens at different times during the period of hibernation. Later it may be possible to make an experimental study of the causes of hibernation and to discuss the relevant literature. But at the moment let it suffice to refer to the following papers, from which the reader may inform himself of the present state of knowledge and theory: de Boissezon (1930), Roubaud (1932), and Shlenova (1933). The paper by Hecht (1933) contains a valuable summary of the subject.

A Parasite which proves to be the cysticercoid of a Cestode was discovered by one of us (A. M. G.) in the course of work on the locust problem in British Chad in 1933–4. The material was sent to the Imperial Institute of Entomology, London, where the other author (A. G. H.) undertook the microscopic examination, measurement and description of the specimens and determined their nature. This is the first time a Cestode larva has been recorded in Acrididae and, as far as can be ascertained, in Orthoptera generally. The original slides have been deposited at the British Museum (Natural History).

1. Megasolena estrix Linton 1910 has been incorrectly classified in the Allocreadiidae.

2. The possession of two pairs of longitudinal lymph vessels, a remarkable hermaphroditic sac as well as other minor characters indicate relationship to the Paramphistomidae.

3. Hapladena Linton 1910 possesses these same characters and is considered related to Megasolena.

4. These characters are considered to be of more fundamental taxonomic value than the position of the acetabulum.

5. A new subfamily, Megasoleninae, of the family Opistholebetidae is named and described.

1. Phaonia mirabilis eggs are laid on the surface of water in tree holes. The eggs are white and have lateral flanges and a ventral keel.

2. Trimorphism is absent during larval life, and, except for size, the newly hatched larva resembles the mature larva, having anterior spiracles, triforous posterior spiracles and complete buccal armature.

3. The larvae are carnivorous and capture and devour mosquito larvae.

4. Eggs hatch in 3–4 days. The duration of larval life is about 4 weeks and that of the pupal stage about 2 weeks.

In India larvae of several species of Anopheles(Culicidae, Nematocera, Diptera) are parasitised by two species of fungi which form numerous large-sized spores in the host. These fungi occur in the haemocele of the Anopheles larva, and in heavily infected larvae the fungus can be seen to fill the entire haemocele from the thorax to the last segment of the abdomen. In many instances mycelia and spores occur even within the head of the insect. The fungi were not observed to invade the anal gills of the larva (except in a solitary instance in which spores occurred within the deteriorating anal gills).

Habitat and Material. Seven specimens taken on the gills of Serranus cabrilla at Plymouth on 11. v. 1934 and kindly presented to me by Dr R. Gurney.

In “A Brief Guide to the Varieties of Anopheles maculipennis” which was published in the Quarterly Bulletin of the Health Organisation of the League of Nations, 3, No. 4, December 1934, it is recorded that five varieties of this species are considered valid and that there is in addition the closely allied species—or a further variety— A. elutus. The provisional key to identification given in the Guide is based on the characters of the eggs of the different forms, but information on other characters is added in parentheses. It includes pro-visional information on the characters of the external spine of the harpago.

The symptoms produced by a green strain of tomato streak virus 1 upon a variety of Solanaceous plants are described. A yellow variant of the streak virus which appears to have arisen during the culturing of the green strain is also described. This variant produces local yellow spots upon all inoculated leaves of White Burley tobacco.

Healthy tobacco plants have been infected with the green strain of the streak virus by spraying them with a virus suspension from an atomiser.

The behaviour of the green and yellow virus strains when, co-existing in the tobacco plant is discussed.

Filtration through graded collodion membranes shows that the two strains have different filtration end-points and that therefore they can be separated by this means. The difference in filterability is considered to be a quantitative effect and cannot yet be assigned to difference in particle size.

Immunity tests have shown that a complete cross-immunity exists between the green and yellow strains of streak themselves, between them and two other strains of streak which produce local lesions and between the green and yellow strains and tobacco virus 1. No immunity was found between the streak viruses and those of tobacco necrosis, tobacco ringspot, tomato spotted wilt and potato virus X.

The yellow strain of streak produced local yellow spots on mature leaves of White Burley tobacco. This suggests that the chlorophyll is actually attacked by the virus, and that the formation of the chlorotic spots is not due merely to the inhibition of plastid formation by the virus.

Since the publication of the original paper by Sowerby (1806) no investigator appears to have thoroughly examined Lernaeenicus spratta; even Scott and Scott (1913) in their monograph do not figure all the appendages.

The question of the origin of the Aphaniptera has been, so far, considered obscure. It is for the supposed complete absence of wings in all stages that these insects have been thought by some authors to constitute a very sharply defined order having no close connection with any other group of insects (Imms, 1934, p. 688; Patton and Cragg, 1913, p. 434). This total absence of wings in an order of insects which has a complete metamorphosis would have given this group a very anomalous position in the insect world, as there is no holometabolous insect known which does not possess wings in any stage of its existence. For this reason Packard's conclusion (1894, p. 331) ‘Indeed, the three-fold division of the thorax referred to should have a priori forbidden the thought of rudimentary wings’, and Patton and Cragg's statement (1913, p. 434) ‘They bear no recognizable traces of wings, and the structure of the thorax makes it very doubtful if they are descended from winged forms at all’, can scarcely be accepted.

In this paper an account is given of new forms discovered by the writer during a survey of the parasites of mussels and cockles, obtained chiefly from the estuary at Conway, but also from other beds on the North Wales coast. The trematode parasites of shellfish in this area have not previously been dealt with, although several forms have been described from the Liverpool Bay area by the late Prof. Johnstone and his colleagues. Few additions have been made to our knowledge of the early stages of British marine Trematodes since the publication of a series of papers by Lebour (1912) and Nicoll (1914).

(A) Enteromonas hominis Fonseca, 1915 (emend. Dobell, 1921) is the correct designation of the flagellate first adequately described as Tricercomonas intestinalis by Wenyon and O'Connor in 1917.

Organisms morphologically indistinguishable, at all stages in the life-cycle, inhabit various macaques (M. rhesus, M. sinicus, M. nemestrinus). I have grown the simian species in “pure” cultures, and have obtained all stages in vitro and in vivo: and I have also obtained evidence—not “experimental ”, but from observed spontaneous spread of infection—that the species in M. rhesus and M. sinicus, at least, are identical.

An attempt to infect a man experimentally, by oral administration of cysts from a pure culture of the simian species (from M. sinicus), was unsuccessful.

(B) Embadomonas intestinalis [ = Retortamonas Wenrich nec Grassi] is probably the correct designation of the flagellate described by Wenyon and O'Connor (1917) as Waskia: and it is the only intestinal protozoon of Man which can be readily cultivated at all temperatures from 15° to 38° C. This species closely resembles several others described from other vertebrates—both warm-blooded and cold-blooded—but the identity of them all is still questionable.

A species similar to E. intestinalis has been observed in macaques by several workers, and has been assumed to be identical on insufficient evidence. Two attempts which I have made to infect macaques (M. rhesus and M. sinicus) experimentally, by feeding on cysts in pure cultures of E. intestinalis from Man, were completely negative.

(C) Consequently, while it seems probable on general grounds that both the Enteromonas and the Embadommas of men and macaques are specifically identical, it is still premature—with only negative evidence for their transmissibility from host to host—to assert this conclusion as a fact.

A new genus is here described for the reception of three species of Mallophaga, belonging to the family Philopteridae, which have up to the present been listed under two separate genera, representing two subfamilies. The hosts of the three species under consideration all belong to the Charadriformes. For the present, three species only are included in this new genus, but it is probable that certain other already described species may ultimately have to be transferred to it.

In 1892 P. J. van Beneden described and figured among some caligids from Africa and the Azores a new genus and species to which he gave the name Pupulina flores. He claimed to have found both sexes of the new parasite, but acknowledged that he had described as male and female of his species two copepods which had previously been designated by different names. They were found upon the same host, a devil-fish, and he believed that they were of the same species. In this, however, he was mistaken, for the specimen he described as the male was really a young female of an entirely different species. Owing to this mistake, together with the very imperfect description of both sexes, Bassett-Smith in 1899 denied the validity of the new genus and transferred Beneden's species to the well-known genus Lepeophtheirus. Following this lead the present author placed it in a key to the species of Lepeophtheirus published in 1905, and it has remained there up to the present time.

Cunliffe (1921) has shown that the various stages of Ornithodoros moubata may be distinguished by slight differences in the shape of the spiracles. Nuttall, Cooper and Robinson (1908) have described in detail the structure of the spiracles of another tick, Haemaphysalis punctata. Otherwise the spiracles of ticks have received little attention except from systematists, and though Nuttall and his collaborators described a closing mechanism in Haemaphysalis, no study of its function was made. In this paper I propose to describe the structure of the spiracle of Ornithodoros moubata, and show how its function may be investigated by experiments.

Prepupae and pupae are shown to lose weight more rapidly at low than at high humidities. This more rapid loss of weight is due to loss of water alone and not to loss of dry matter.

The limits of temperature and humidity which each of the two stages can survive have been mapped out. If the metamorphic period as a whole is considered, it is likely that the limits of temperature and humidity for survival and development will be narrower than for each stage considered alone.