In January 1954 I received from Dr Harry Hoogstraal of the United States Naval Medical Research Unit no. 3, Cairo, Egypt, a collection of ticks for investigation. In the monograph of Nuttall, Warburton, Cooper & Robinson (1911) these specimens were run down to Ixodes ugandanus Neumann, but in view of the constant differences between them I recognize the present material as a new species. I assign the name hoogstraali to them in consideration of Harry Hoogstraal's kindness and generosity in supplying me with tick material. Unfortunately the entire collection consists of females.

1. Three species of flea were found on rats caught on the docks of Plymouth, England, namely, Nosopsyllus (Ceratophyllus) fasciatus, Xenopsylla cheopis, and Leptopsylla segnis (musculi).

2. The findings of Xenopsylla cheopis were almost entirely confined to a certain grain store, whence the flea was obtained constantly throughout the period of the investigation.

3. A few rats caught in the town of Plymouth yielded Leptopsylla segnis and Nosopsyllus fasciatus, but no Xenopsylla cheopis.

In the course of investigations on the Gregarines of Cirratulus (Audouinia) tentaculatus Mont., I have frequently noticed a large astomatous ciliate in the intestine. This appears to be Anoplophrya brasili described by Léger and Duboscq in 1904. One or two points, however, have led me to make a closer study of this organism, and I have come to the conclusion that it should be removed from the genus Anoplophrya.

The term trypanosomiasis is applied to-day to a group of diseases affecting vertebrates and caused by parasitic Protozoa belonging to the family Trypanosomidae. These parasites occur chiefly in the blood plasma and the typical form possesses an elongated body, an undulating membrane, a single nucleus, a blepharoplast, and a chromatic filament running along its length from near the blepharoplast, along the margin of the undulating membrane, to terminate freely at one end of the body. The latter has a somewhat spiral form, the protoplasm being alveolar and at times showing a granular structure. An axial filament has been described as occurring in some forms. One species, Trypanosoma equiperdum, occurs largely in the lymph, and another, T. gambiense, may invade the cerebrospinal fluid. They are actively motile organisms, multiplying usually by longitudinal or multiple division. Numerous species of trypanosomes have been successfully cultivated in vitro in the presence of haemoglobin, and by this means many trypanosomes have been discovered in animals in which these parasites occur in such scanty numbers that their presence cannot be detected microscopically. Thus, a large percentage of birds and cattle in different parts of the world have been found to harbour trypanosomes in their blood.

During the past three years I have made various attempts to raise Dermacentor variabilis through its various stages on tame rabbits and have at last been successful. Though there are still many points connected with the life-history to clear up, it is at any rate the first step towards finding ways and means for its control.

R. cesticillus was found to undergo a diurnal migration in both multiple and single worm infections of the fowl. This migration involved movement of both scoleces and strobilae and occurred in an anterior direction when the intestine was empty of food, and in a posterior direction when the intestine contained food. The relevance of the migration to the histological picture of the worm in situ is discussed and some possible explanations for the migration are suggested.

Infective Haemonchus contortus cayugensis larvae were harvested from faecal cultures, cleaned and stored at 4°C. By means of small sample runs, exsheathment rates were determined for batches of clean larvae prior to and during storage. The larvae were stimulated to exsheath at 40°C in 0·02 m-Na2B4O7. 10H2O into which a gas mixture of 40% CO2–60% N2 was bubbled. A 20 and 60 min exsheathing time produced some and no decrease in exsheathment rates respectively for freshly cleaned unstored larvae and larvae stored 1–12 weeks. In all instances there was a reduction in the exsheathment rate 24 h after the larvae were placed in cold storage. This was considered a result of a cold shock from which the larvae did not recover until after the fourth day.

In a literature search for species of Pterygosoma it has been my good fortune to find a figure and Japanese description of Pterygosoma japonicum Kishida, 1927, in Figuraro de Japanaj, Bestej Tokyo, 1927, Hokurykan and Co. Ltd. This specieshas not been listed by the Zoological Record, and indeed it seems to have been completely overlooked in the West. Hence this re-publication.

I feel greatly honoured to have been asked to speak to you about Alphonse Laveran. Professor Garnham wondered if I had met Laveran and what was the State of his relations with Professor Emile Brumpt my father. I have known many Pastorians: Emile Roux, Mesnil, Marchoux, Roubaud, Charles Nicolle, but unfortunately not Laveran.

Whilst engaged in rearing a number of bed-bugs, the variation recorded below was observed in an individual that had just moulted from the first to the second nymphal stage. As such an abnormality does not appear to have been previously described, it seemed worth while to place it on record.

As the infection progresses in lambs, the developing germ cells of male Nematodirus battus become filled with lysosome-like bodies, electron-dense granules and membrane-bound vesicles, and the organization and division of the gametic nucleus appears to be altered. The epithelial cells of the reproductive tract are also damaged and the secretory-type globules produced by the cells of the vas deferens are denatured. These changes are compared with ultrastructural changes observed in other species of nematode affected by the immune response of their hosts.

During August 1953, the Hon. Miriam Rothschild, with the assistance of Dr Schifferli and Fritz Muhlethaler, succeeded in obtaining three nests of the Alpine chough Pyrrhocorax graculus L. on the Niesen (1200 m.) Bernese Oberland, Switzerland. Three nests of the snow finch Montifringilla nivalis L. were collected during the same period from behind gutters and under eaves on the railway buildings at Eigergletscher (2320 m.), Bernese Oberland, immediately after the young birds had flown.

To summarize our principal observations made in the course of the investigation into the rat-fleas of the suspected plague area of East Suffolk, July—October, 1911:

(1) We found an average of four fleas per rat: 822 rats were examined and 3293 fleas taken.

(2) The average was subject to a local variation (0·6 to 6·5).

(3) 15 species of fleas were taken from the rats, but of these there were only two species, C. fasciatus and C. agyrtes, which occurred in any numbers.

There were C. fasciatus 1986 or about 60 per cent.

C. agyrtes 1257 or about 38 per cent.

Rare species 50 or about 2 per cent.

(4) The average number of fleas per rat and the percentage of rats infested by fleas showed a well-marked seasonal variation, there being a considerable decline in the numbers as the cooler weather came on. Ceratophyllus fasciatus and Ctenophthalmus agyrtes both participated in a similar way in this variation.

(5) C. fasciatus is chiefly found on rats caught near human habitations; C. agyrtes on those caught in the hedgerows.

Types. Four mature females (NM. 5728) from Myotis tricolor, Town Bush Cave, Pietermaritzburg, March 1952.

No Worker on British Turbellaria having hitherto given any attention to parasitic species, I devoted the greater part of my visit to the Laboratory of the Marine Biological Association, Plymouth, Aug.–Sept. 1933, to the collection and investigation of these forms. The number discovered is small in proportion to the number of hosts examined. All but the last have been identified from von Graaf (1913), and all but the first and last are new to the British fauna.

It is well known that the ectoparasitic Arthropods often produce in their host various skin reactions such as macules, wheals and haemorrhages, which in many cases are due to the salivary secretion of these ectoparasites. Nuttall and Strickland (1908) were the first to find an anticoagulin (called “Ixodin” by Sabbatani) in the salivary glands and alimentary canal of Argas persicus. Bruck (1919) found that the organs of Culex contained a haemolytic- and urticaria-producing substance called by him “Culicin.” His study was not, however, precise, because he ground up the entire bodies of the gnats, thereby mixing up secretions, excretions and fragments of organs, some of which would never enter a wound in the process of blood sucking. Moreover, the urticaria following mosquito bite was found by Schaudinn to be due to the yeast present in the oesophageal diverticula of mosquito. Klausner (1916) states that the secretions of the salivary glands in Cimex are soluble in water and alcohol, are haemolytic and produce urticaria; he found also that they do not contain formic acid and that immunity to their effects is not acquired. Nuttall (1918) dealing with the effects of salivary glands of Phthirus on human skin states that the bluish spots of the skin are especially marked after biting of adult lice, that they have nothing to do with the blue spots in the fat body of the lice and that they are probably derived from the exuded and altered blood of man.