Thomas W. M. Cameron

Studies on Three New Genera and some Little-Known Species of the Nematode Family Protostrongylidæ Leiper, 1926

The classification of the nematodes occurring in the lungs (and related forms) of land mammals has always been one of considerable difficulty, in large part because of the existing very inadequate descriptions of many of the commoner forms. Most systematic helminthologists have followed and amplified the classification adopted by Railliet and Henry in 1907, a system which divided these nematodes into three main groups — those found in the blood-stream ( Haemostrongylus ); those found in the larger bronchi ( Dictyocaulus, Metastrongylus and Crenosoma ); and those found in the minute bronchi and alveoli ( Synthetocaulus ). While the first two groups contain four well-defined zoological species, an examination of the forms included in the genus Synthetocaulus shews that it consists of a heterogeneous collection of species, which, although possessing a common habitat, are by no means so closely related as has been supposed, and, indeed, belong to several different genera.

On Two New Species of Nematodes from the Scottish Red Deer

During the examination of an abnormal specimen of the Scottish Red Deer ( Cervus elaphus ) in the winter of 1930, my colleague, Mr. W. C. Miller, M.R.C.V.S., discovered several specimens of a bursate nematode lying on the connective tissue between the latissimus dorsi and the external intercostal muscles. Struck by the unusual habitat of such a worm, search was subsequently made in similar situations in other deer, and in two animals the same parasite was found.

Observations on the Life History of Ælurostrongylus abstrusus (Railliet), the Lungworm of the Cat

A Preliminary outline of the life history of the lungworm of the cat and its confusion with that of Ollulanus tricuspis, has been given in a previous paper. Since that paper was published, the name of the family of lungworms has been changed to Protostrongylidae by Professor Leiper; and an examination of adults of the lungworm from the cat, shewed that it belonged to a different genus from the type of the old genus Synthetocaulus. To this new genus, the name aelurostrongylus has been given.

On a New Species of Oxyurid from the Grey Squirrel in Scotland

The grey squirrel ( Sciurus carolinensis ), although of comparatively recent introduction from North America, has become thoroughly acclimatised and may now be regarded as one of the native British Mammals. Comparatively little is known of its helminth parasites and the following oxyurid, found in the large intestine of a specimen shot in the north of Scotland, appears to be undescribed.

Experimental Infection of Sheep with Dicrocœlium dendriticum

Five years ago, while on a visit to Glasgow, my attention was drawn by Mr. Peter Braid, M.R.C.V.S., to the occasional appearance of Dicroœlium dendriticum in the liver of sheep from the West of Scotland. Mr. Braid arranged to supply me with such livers as in future came to his notice and to ascertain, where possible, the place of origin of the sheep. In this way, I have received from him livers from sheep which came from Tiree, South Uist, Barra, Harris, Campbelltown, and from Berwickshire, Ayrshire and Lanarkshire. Enquiries locally at these places shewed that some at least were mere markets. In Berwick, for example, sheep were on sale which had come from the West; and in the West, sheep which had originated in the islands. In the case of the Hebrides, however, sheep are not habitually imported for subsequent re-sale and the great majority—certainly all the young animals—are bred locally. It seemed legitimate to conclude therefore, that in these cases, the disease also was acquired locally. The various islands were visited in autumn, 1929, and Tiree was selected as affording the best and most convenient situation for an investigation into the life-cycle of the parasite.

On the Pathogenicity of the Stomach and Lung Worms of the Cat

In 1890, Muller described, from the lung of the cat, a species of nematode which is now known as Aelurostrongylus abstrusus . In 1928, I was able to show that its true habitat was not the lung substance, but the pulmonary artery and its branches, and that its pathogenic action, was mainly, if not entirely, due to the presence of the developing eggs and larvae distributed throughout the lung tissue by the blood stream.