Amblyomma hebraeum males anchor immediately when placed in a hungry state upon the host. The females will not do so as a rule in the absence of previously anchored males. Usually the males do not move or scarcely move when once anchored on the host, they may continue to remain attached to the host for months after the females have dropped off gorged. The males, after having fed for a few days, show signs of sexual excitement in that they erect their bodies away from the host and extend their legs, whereby, without releasing their mouthparts from the host's skin, they seize and hold any females that chance their way. The males become excited when the skin of the host in their vicinity is handled, no females having been near them for months. To copulate, the males must necessarily release their mouthparts, and this may at times lead to their shifting their position. They may occasionally shift to a fresh anchorage in company with their females, or they may shift a few mm. when apparently alone. A male may copulate with several females. The coloration of the male changes after prolonged sojourn upon the host (77–141 days).

After feeding for 2–8 days or more, the females wander and are grasped by anchored males so that the ticks' ventral surfaces are apposed, and in this position the female proceeds to feed with her mouthparts puncturing the skin of the host in close proximity to those of the male. Copulation takes place in due course, the male temporarily removing his mouthparts from the host for the purpose. A female may seek two males in succession but usually one male appears to suffice. Females feed very slowly in the absence of males, they gorge rapidly when fertilized, and, when fully gorged, usually abandon the host without delay. Depending upon their having access to males and access to a more or less adequate food supply from the host, the females remain upon the host for 4–25 days before dropping off in a gorged condition.

Hyalomma aegyptium males anchor immediately when placed upon the host. In the absence of females they remain fixed or change their position but slightly at long intervals of time. When hungry males and females are placed together upon the host, they proceed to suck blood at once, and, after a preliminary feed lasting five or more days, the males wander in search of females. A male may copulate with several females. Females placed in close proximity to males cause these to become excited (as in A. hebraeum). The females as a rule do not change their anchorage upon the host from start to finish, being sought by the males. The latter stay upon the host indefinitely (122 or more days) after the gorged and fertilized females have dropped off.

Rhipicephalus bursa males and females, when hungry, proceed to feed at once when placed together upon the host. After remaining fixed for 3–5 days, the males seek anchored females. The males may seek a number of females in succession, usually feeding for some days prior to seeking a fresh female. Males continue to wander from anchorage to anchorage in the absence of females, they may thus wander about for 86 days or longer after the females have abandoned the host. A male may copulate with several females.

The behaviour of the sexes differs therefore in the three foregoing species. In A. hebraeum the females seek the males, in H. aegyptium and R. bursa the males seek the females. In all three species the males remain upon the host indefinitely after the females have dropped off. In R. bursa the males continue to wander about from anchorage to anchorage long after the females have left, whilst in A. hebraeum and H. aegyptium the males stop their wandering entirely or shift but slightly at longer intervals of time.

The predominance of male ticks of any species upon a host under natural conditions is accounted for by their staying on and accumulating upon the host whilst successive lots of females drop off. As an example I may mention that I have seen camels in Biskra on which only males of H. aegyptium could be found; these males must have been a very long time upon the camels because their scutums were polished and scratched, the rugose surface so characteristic of the young male tick having been worn away.

Copulation in all three species was observed on several occasions upon the host, the process lasted 10 minutes or longer and was similar to that described by me for Ornithodorus and Ixodes.

Since the liability to injury increases with the degree of engorgement of the female tick it is a great safeguard to her that she attains her full state of engorgement rapidly at the end of her feeding period and that she drops from the host promptly.

Trypanosoma (Nannomonas) godfreyi sp. nov. from tsetse flies in The Gambia: biological and biochemical characterization

Parasitology109, 497–511

p. 499, para. 2, 104/ml to replace 104/μl

p. 501, para. 1, chromsomes to replace chromosome

p. 501, para. 2, 1/148 to replace 1/48

p. 504, para. 3, BAN 9 or KEN 7 to replace BAN 9 & KEN 7

On February 8th, 1923, I received three examples of living larvae of Musca domestica, from Dr James A. Stephen (Head of the Child Welfare Department of the Public Health Service, Aberdeen) with a statement that they “came from the bowel of a child, 4 months old, breast-fed, but having sugar on a teat.”

Only a few years ago parasite immunology looked an unattractive subject better left to the dogged specialists. Parasites and hosts had been playing chess together for a million years, and there seemed little prospect of perturbing matters in favour of the host immune system. All that has changed, for three reasons. Firstly, we have learned how to grow at least some parasites in vitro, and prospects of doing so with others are encouraging. Secondly, progress in cellular immunology has revealed the sort of loopholes in the host defence system which parasites are likely to exploit: we are learning the questions which matter about parasites as antigens. Thirdly, and most importantly, molecular genetics is being brought to bear on parasites: we can now see a real, though long-term, prospect of manufacturing practicable vaccines through bio-engineering, and more immediately it gives us the tools needed to probe the host immune responses in the form of cloned antigens.

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.

This study compares papillae distribution in seven microphallid cercariae of the genera Microphallus and Maritrema. Certain papillae or groups of papillae have generic, supra–generic or specific significance. Microphallidae are characterized by the absence of C I cycle and of dorsal P II and P III, the presence of one C II1 and one C II2, of four mediodorsal A I D papillae and of two horizontal papillae on the tail. The number and disposition of the papillae at the front of the body (peribuccal and anterodorsal A I D and St DL) and at the back (P cycles) have a generic significance. The number and disposition of the papillae in the middle of the body (A and M cycles) have a specific significance.

In 1951 the laboratory examination of birds at Fair Isle Bird Observatory was extended to include the collection of ectoparasites. The fleas collected during the years 1951–55 have been recorded by Rothschild (1958).

Two adult females bearing males, on the gills of Trigla cuculus at Plymouth, collected by Miss Miriam Rothschild in November 1933.

When I graduated as a Veterinary Surgeon some 36 years ago, the number of effective anti parasitic components available for clinical use were remarkably few. Many natural products were still in use (extract of male fern, arecoline, oil of chenopodium, kamala, nicotine, derris and the like) many difficult to formulate and to administer, some requiring overnight fasting before use and purgation after use. The compounds of remarkable promise at that time were phenothiazine for nematodes in farm animals, carbon tetrachloride for liver fluke in sheep and cattle, the sulpha durgs for coccidia and two wonder drugs for the arthropods, DDT and BHC.

In this section are collected all the instances recorded at this laboratory of the testing of T. gambiense on man, after the trypanosome had been maintained for a time in laboratory animals.

Two mature worms of this species were recovered from the small intestine of a Common Snipe, Gallinago gallinago (Liun.), shot on a Cardiganshire moor in July 1935. Three mature worms were again obtained from a Common Snipe shot on the same moor in the third week of October 1936, just prior to the arrival of the migrant snipe.

The temporal distribution of hatching of the embryonated eggs of Transversotrema patialense has been examined under different temperature and illumination regimens. Under a DL 12: 12 regimen at 30°C egg hatching exhibited a circadian rhythm with a period of 24 h. Within a diel time-frame hatching was distributed over the final 9 h of the light period with less than 2% of the eggs hatching during the dark period. This pattern was temperature independent over the range 25 to 30°C and persisted under constant illumination. It is suggested that the timing of hatching is under endogenous control and is functionally related to a circadian rhythm of behaviour of the intermediate host mollusc, Melanoides tuberculata.

Histochemical analyses of the pigment accompanying lung mite infections in Old World monkeys indicate that, contrary to other endogeneous pigments, this pigment is not homogenous, but consists of at least three components. One fraction is formed by fine granular or amorphous cleavage products of mucin substances, the second portion appears to be large granules of haemosiderin and/or lipofuscin, and the third component consists of needle-like crystals of unknown chemical nature. The source and nature of the pigment are discussed.

I am grateful for the technical assistance of Mrs J. A. Silva and the support by Drs R. T. Damian, S. S. Kalter, R. E. Kuntz and B. J. Myers; Southwest Foundation for Research and Education, San Antonio, Texas.

This study was funded in part by U.S.P.H.S. Grants RR-00361, RR-00278 and RR-00451 and WHO Grant Z2/181/27.

In the course of dissecting a parakeet (Brotogerys tirica) sent to me for examination, I came across several large tapeworms of the genus Cotugnia in the duodenum. They did not agree with any of the species previously described and, upon closer examination, showed so many points of difference as to justify the creation of a new species for them. I propose the name Cotugnia brotogerys for this species.

Among over 700 Australian birds dissected, Geopetitia spp. were found in three. These are described as new species, as follows: G. streperae from Strepera melanoptera, G. chibiae (female only) from Chibia bracteata, and G. falco (female only) from Falco longipennis.

Types of the new species will be deposited in the South Australian Museum. Paratype material of G. streperae will be in the Helminthological Collection of the Zoology Department of the University of Adelaide.

The three birds from which the Geopetitia spp. were taken were collected by ornithologists of the South Australian Museum, to whom I am most grateful.

The accurate identification of cestodarian and cestodan helminths depends so much upon the correct interpretation of their internal morphological features that a rapid yet satisfactory routine technique in their preparation for microscopical examination is much to be desired. Not all workers publish their technical methods, and, among those who do, no two seem to be in agreement. Some of the collection and preservation methods, in particular, which are advocated, whilst admirable for museum specimens or histological study, are impracticable under the conditions of a field survey, where many host animals have to be quickly examined and rapidly accumulating specimens are preserved and studied by methods which will not strain unduly the limited facilities of a field laboratory or a small biological station.

Stages of incomplete division of chains of individuals in the species Herpetomonas bancrofti, as well as the distribution of abnormal cells within long chains, were found to support the writer's earlier view (Holmes, 1931) that successive longitudinal divisions of individuals occur within chains. In this type of division there is alternate splitting of individuals from anterior and from posterior ends of cells. It is concluded that this hitherto unproved type of division of pairs and chains is sufficient to account for the presence of all observed aggregates.

No evidence was found suggesting occurrence of any essentially different type of cell division, such as the transverse fission reported by Franchini (1931, 1931 a) as possibly accounting for formation of chains in H. ganorae.