The hypothesis that human malaria is transmitted by mosquitoes was canvassed by Laveran, Manson, Bignami, Dionisi, Koch, and others in 1895–1897—to mention no earlier speculators. But when, and by whom, was this hypothesis converted into a fact?

The following brief communication presents another instalment of experiments on the effects of prolonged direct transmission upon trypanosome strains kept up in the laboratory.

Ce trématode a été trouvé par Nicoll dans l'intestin du Totanus calidris L. dans la Grande-Brétagne.

Our freshwater fishes have for long been a subject of some economic interest and in consequence their diseases and their parasites have received quite a considerable amount of attention. Much has been written on the subject, even in this country, and it has formed the basis of not a little speculation and possibly some results of economic value. As usual, however, more attention has been devoted to the matter on the continent and in America. It is, nevertheless, gratifying to find that Mclntosh (1863) was one of the first to realise the important help to be derived from a scientific study of fish parasites in investigations on such problems as migration, etc. His work has been greatly amplified by the later researches of such men as Hofer (1904) and Zschokke (1884–1914) in Europe, and Ward (1908–11) in America, to mention only a few well-known names which have been prominent in this line of investigation.

1. Ixodes holocyclus is a three-host tick.

2. It is found on native mammals, being abundant on Perameles nasuta (the bandicoot), while it has also been found on dogs, cats and man, and exceptionally on the large bush opossum and the rat.

3. Eggs hatch in from 49–61 days in warm weather.

4. Larvae harden and become active in about seven days, and engorge on host in 4–6 days.

5. Larval metamorphosis is prolonged by cold, and is most rapid in warm weather, varying from 19–41 days.

6. Nymphs harden and are quiescent for about seven days, and engorge in 4–7 days.

7. Adults emerge from larval skin in 21–71 days.

8. Coupling occurs away from the host and may last 11 days.

9. Adults harden and seek the host in about seven days and engorge in from 6–21 days.

10. Males are only rarely found on hosts, and have never been found attached or showing signs of engorgement.

11. Oviposition begins 11–20 days after the female leaves the host, and may last from 16–34 days; the number of eggs laid being about 1800–2500.

12. All stages are soon killed by desiccation, gorged nymphs and larvae being very soon killed even at moderate temperature.

13. A mass infestation with Ixodes holocyclus has not been seen either on native or domesticated animals.

We had the opportunity of examining about twelve snakes (Tropidonotus natrix) all from the same district, and found in almost every case a heavy infection with various Trematodes. In the lungs we found Saphedra longicollis, and in the small intestine Leptophallus nigrovensis and Cercorchis nematoides, together with several specimens of Odhneria bolognensis n.g., n.sp. We will discuss the systematic position of this new genus in another part of this paper.

The differences noted between these Sarcoptes from cattle and those from the horse, described by Buxton, are as follows:

There are two lateral setae in all stages. The spines are notched or V-shaped at the ends. There are three cones in the larva as well as in all other stages. There is a pair of setae analogous to that found on the genital apron of the male at the corresponding location in the immature female. In the immature female the ridges on which are located the third ventral setae (V 3) run backward without returning forward on the opposite side. In the adult female, immature female and male, the two short setae on the terminal joint of the first leg, P 7 and 8, are represented by a single seta on the second leg. The third leg in all stages is furnished with four short setae on the terminal joint. The end joint of the fourth leg of both adult and immature females has four short setae. In the nymph none are present on the fourth leg.

The salivary glands (Fig. 1) consist of two pairs situated between the anteriorly protruding coeca of the midgut. The one pair are bean- or kidney-shaped (b) the other horseshoe-shaped (h) and extend further backward close to the gut. The four ducts of these glands run forward along the oesophagus, unite, and form a common duct emptying between the dorsal and ventral chitinous stylets of the mouth-parts.

With the exception of the Handbook of Braun and Lühe (1910) and two papers by Gough (1911) and Baylis (1922), very little has appeared dealing with the technique of the examination of cestodes, in particular no special methods for their rapid examination have been described. Fixing, staining and mounting, with the washing necessary at various stages in the preparation of cestodes, may occupy from two to five days. Some other quicker process is obviously needed, this it is the main object of the present paper to supply. The following methods should be understood to apply to fresh material.

Anthomyia pluvialis Linn. (1761) is a very common and beautiful fly, widely distributed in the old world, and easily recognisable by having characteristic black spots on the thorax and abdomen.

Es ist schon längst die weit verbreitete Hautkrankheit des Menschen bekannt, welche in Russland bildlich als “Wolossatik” bezeichnet wird. Dieser Volksname findet seine Erklärung im Aberglauben der Bauern, welche überzeugt sind, dass ein ins Wasser gefallenes Pferdehaar auflebe (Verwechselung mit dem Gordius aquaticus). In solchem Zustande solle es manchmal beim Baden oder Waschen in die Haut des Menschen eindringen, wo es sich bewegt, ein Jucken verursacht und in der Haut eine rötliche, leicht angeschwollene Spur resp. eine mehr oder weniger gewundenen Linie hinterlassen kann. Diese Krank-heit wurde beschrieben (1) von Lee, welcher in der Clinical Society of London, 1874, einen Vortrag über einen Fall der Kriechkrankheit (Creeping eruption) gehalten hat, und (2) von Samson, welcher 1895, in Wratsch einen Brief über eine neue Hautkrankheit veröffentlicht hat. Auf Samson's Brief folgten bald analoge Mitteilungen Ssokolow (1895), Kuschen (1896), Olissow (1897), Kum-berg (1898), Rownitzky (1898), Wostrikow und Bogrow (1909) in Russland und Lee (1884), Malcolm Morris (1896), Neumann (1895), Kaposi (1898), Harlingen (1902), Boas (1907), Fülleborn (1908, 1918), Knowles (1916), León (1914) u. a. in West-Europa und Amerika.

The reputed toxic and destructive action of certain species of Chara led to the preparation of watery and alcoholic extracts of Chara foetida and C. hispida which were sent to me with the request that the larvicidal power of these extracts should be tested.

In laboratories which are situated either abroad or in districts at some distance from commercial centres, it often happens that needed apparatus is difficult to obtain, and these notes may be helpful to workers in such situations.

The stink organs are different in structure and position in the adult and the larval stages.

The stink organs of the adult are composed of (a) a pair of glands, (b) a central reservoir with two backwardly-directed lateral reservoirs, (c) a median kidney-shaped organ in the central reservoir, and (d) a pair of lateral external openings.

Each gland is a multicellular compound structure, opening into the central reservoir. It is described for the first time in this paper.

The whole of the stink organ of the adult is formed in the last larval stage from a pair of invaginations of the epithelial lining of the body-wall.

In the larval stages the stink organs are simple glands, situated dorsally in abdominal segments III to V.

The function of the stink organs is defensive and in the adult perhaps also sexual.

The host of this gregarine is Dacne rufifrons Fabr., a small beetle, which is commonly to be found feeding on the polypores which grow on old elm trees in the neighbourhood of Cambridge. Beetles collected in the Autumn, and again in the following Spring, were very heavily parasitized. The beetles live together in small colonies, a habit which greatly increases the chance of infection.

In the upper part of the small intestine of a Bennett's kangaroo, Macropus bennetti, there was found many parasitic worms which, although closely related to Nematodirus, differ from members of this genus sufficiently to warrant separation into a distinct genus.

(1) Forcipomyia is one of the few genera of the Ceratopogoninae (Chironomidae) whose larvae are not aquatic. They retain, however, the apneustic condition typical of the entire family, and are therefore compelled to live in moist places such as beneath the rotting bark of fallen trees, in the hollow tap roots of dead plants, in wounds and rot holes in trees, in drying horse and cow manure, in decaying fungi, and in the nests of ants. The immature forms are strongly gregarious.

(2) The larvae pass through four stages, each lasting about a week; the successive changes in chaetotaxy at each moult is recorded in the discussion of F. picea. All known European species of this genus hibernate as third or fourth stage larvae. The duration of the pupal stage is about one week; the length of life of the adult has not been determined. There are usually three generations per annum. The adults are known to suck the blood of other insects.

(3) The larvae are eucephalous, more or less cylindrical, 3–6 mm. long, with eleven clearly denned segments (three thoracic and eight abdominal, the eighth divided into two apparent segments). Progression is achieved by means of a retractable, biramous, prothoracic pseudopod, and a ventral hook-studded ridge on the ultimate abdominal segment, with the occasional aid of the mandibles.

(4) The head and body bear numerous lanceolate and simple hairs of great specific importance.

(5) The mouth-parts consist of a fleshy labrum, a pair of small premandibles, a pair of long, slender mandibles working in the sagittal plane on either side of the labrum, a pair of reduced maxillae of fleshy nature with chitinous internal supports, and a simple untoothed labium. Within the head there is a complicated chitinous structure, the hypopharynx; this is figured and described in full detail and its action in comminuting the food is revealed for the first time.

(6) No investigation has hitherto been made of the internal anatomy. The alimentary canal, consisting of buccal cavity, hypopharynx, oesophagus, mid-gut, and hind-gut, is quite simple in structure, without nodules or caecal chambers. It is only slightly longer than the body, a loop occurring in the hind-gut when the larva contracts.

(7) The malpighian tubules are either two or three in number, the latter condition being unique among insects. The third is ventral, passing into the posterior part of the body only.

(8) The salivary glands are a pair of S-shaped bodies closely adhering to the walls of the anterior portion of the mid-gut; they are chiefly composed of large binucleate cells.

(9) The circulatory system consists of a dorsal vessel extending throughout the body and passing between the lobes of the brain above the oesophagus into the head. In the eighth abdominal segment it enlarges slightly to form the heart, with one pair of ostia or valves situated on its posterior extremity.

(10) The nephrocytes are arranged segmentally, four to each abdominal segment and a single mass in the thorax, all attached to the dorsal vessel. The excretory function of these cells was demonstrated by injection of ammonia-carmine into the body cavity.

(11) The nervous system is only very slightly cephalised, there being seven ganglia for the eight abdominal segments and three in the thorax; the normal bilobed brain is situated in the thorax in all larval stages. The sympathetic system is described, and differs somewhat from that of its close relative, Chironomus.

(12) Despite the absence of spiracles there is a well-developed tracheal system in the form of two main trunks with transverse connections, branch tracheae, and subcutaneous plexuses.

(13) The muscular system, oenocytes, fat-body, and gonads have also been studied in detail.

(14) The larval skin is retained upon the last four or five abdominal segments of the pupa.

(15) The characters used for determining the species, in their order of importance, are as follows: Larva: chaetotaxy, prothoracic pseudopod, markings of the head, anal blood-gills. Pupa: cuticular spines, prothoracic horns.

(16) The larvae and pupae of nine species of Forcipomyia are described with particular reference to their specific characters. Descriptions of the adults of two new species, F. radidcola and F. pulchrithorax, by Mr F. W. Edwards, are appended.

(17) Closely related forms are Euforcipomyia and other exotic subgenera not yet named, and the genus Atrichopogon (now including Kempia). Dasyhelea belongs to this group of hairy-winged flies, but its larvae partly resemble those of the bare-winged Ceratopogonines in that they have lost the pro-thoracic pseudopod and macrochaetae, but retain the anal hooks.

In the body-cavity of a Racket-tailed Drongo (Dissemurus paradiseus) which died at the Calcutta Zoological Gardens, and the blood of which was teeming with two species of microfilariae, were found males of two new species of filariae, together with a single female specimen. In a Hunting Cissa (Cissa chinensis), which died at about the same time, males of one of the species discovered in the Drongo were found again, accompanied by a single female different from that found before. Since this cissa also harboured two species of microfilariae in its blood, the identity of either of the females is doubtful. In another specimen of hunting cissa a single male specimen of an entirely different species, which I have made the type of a new genus, was found. Here again two species of microfilariae were discovered so that it is not possible to say which is the offspring of the adult found. It had been hoped that more infected specimens of these birds might be obtained so that the confusion as regards relationships of the females and offspring to the males might be cleared up, but there appears to be little hope of more being obtained in the near future.

Host: Xylocopa aestuans (Linn.). Locality: Lahore, India.

The gregarine described below has been found abundantly in the alimentary canal of many specimens of the carpenter bee, Xylocopa aestuans (Linn.), and is the first to be described from any Hymenopteran host. Keilin (1918), in describing Leidyana tinei in a Lepidopterous larva, remarked that no gregarines had been found till then in the two large orders of holometabolic insects: Lepidoptera and Hymenoptera. He further observed as follows: “The fact that gregarines have not been previously recorded in these two orders cannot be considered as due to lack of observation, since large numbers of these insects have been dissected for many different purposes. Possibly we can account for the infrequency of their occurrence because of the habits of the larvae of Lepidoptera and Hymenoptera. These are often parasites in other Arthropods (Hymenoptera) or they are gallicolous (Hymenoptera) or phytophagous (Lepidoptera and Hymenoptera) or they live in nests and cells (Hymenoptera).” We have examined about 200 specimens of Xylocopa and found them practically always infected.

The material described in this paper was obtained from a mongoose (Herpestes albopunctatus Hodgson 1853), dead twelve hours when dissected. In the mesentery were numerous larval cestodes and in the intestine approximately fifty adults of another species. The preservation was good. The preservation was good. I wish here to acknowledge my indebtedness to Mr G. D. Bhalerao, M.Sc., of this University, for the help given me in the preparation of the specimens.