In the early spring of 1931 one or two hibernating adults of Phyllotrela undulata Kutsch., recovered from a piece of tree bark, were dissected by chance and found to be parasitized by a nematode. Realising that the host insect was not only of wide distribution throughout the country but also that, amongst farmers and other crop growers, it was known as a serious and destructive pest, this accidental record of parasitism led the writer to enter upon the present study.

Before dealing in detail with certain aspects of the research work on the potato eelworm which has been carried out by the present writer an account of the occurrence of the parasite in Ireland must be given.

Dogs are notoriously susceptible to helminthic infections, especially of the alimentary tract. Their role as carriers of such important pathogenic organisms as Echinococcus and Taenia multiceps makes the study of their parasites of more than academic importance, so much so that by an order of the United States Bureau of Animal Industry, all sheep dogs imported into the U.S.A. have to be held in quarantine pending a faecal examination for helminthiasis (Wigdor, 1919). Statistical surveys of the helminth parasites carried by dogs have already been made in a number of different countries. In this country the subject has been studied by Lewis at Aberystwyth, in Wales; and by Nuttall and Strickland in Cambridge. Brown and Stammers have made a parasitological survey of the dogs in London based on post-mortems combined with examination of faeces from London pavements.

The hermaphroditic Trematodes from the blood vessels of the turtles are included under the Family Spirorcbidae and represent several genera differing from each other in several features, including the general topography of the genital organs. It originally contained only two genera—Spirorchis and Hapalotrema, differing from each other in the number of suckers, the relative position of the genital glands and the number of testes. Owing to these unique differences between them they were referred by Stunkard (1921) to two subfamilies—Spirorchinae and Hapalotreminae. The work prior to 1923 is summed up by Stunkard (1923) in a brilliant memoir, where, besides describing two new genera, one under each of the two subfamilies, from North American turtles, he has clearly elucidated some important points of systematic nature. Subsequently, the same author has considerably added to our knowledge of the group in several memoirs mentioned in the list of references at the end of the present communication.

The developments which have taken place during recent years in the scientific management of grassland have resulted in a marked improvement both in the quality and in the quantity of the herbage produced. This has been brought about partly by frequent manuring, particularly with nitrogenous manures, and also by ensuring the close cropping of the grass at frequent intervals.