In 1925, Morgan, in recording field observations on Heterodera schachtii in the Kirton district, pointed out that cysts were frequently as abundant in certain areas of infected fields where the yield was satisfactory, as in “bad patches” where the plants showed every manifestation of eelworm disease, and where the crop was a failure. In a further publication (1926) he again emphasized the lack of correlation between cyst content of the soil and the incidence of “potato-sickness.” One field on which detailed observations were carried out, although the worst case of eelworm infestation examined in the district, was found to give a satisfactory crop—average yield eight tons ware per acre—after only a four year rotation. In summing up these observations, Morgan says: “While it is not suggested that the eelworm had no influence on the yield in this instance, the success of the crop in spite of the pest lends support to the view that the problem is primarily one of obtaining more suitable conditions for plant growth by more judicious manuring and a system of rotation.”

Aphelenchus ritzemabosi is known as a serious parasite of greenhouse plants such as chrysanthemums and gloxinias but the number of records of its attacks on plants grown out of doors is increasing. Disease due to it has been observed in the open on chrysanthemums and dahlias in this country and in the present paper a new out-of-door host is added to the list of plants attacked by it.

Hymenolepis diminuta (Rudolphi, 1819), a normal inhabitant of thesmall intestine of the rat and other rodents and occasionally to be foundin man, has* received attention from several investigators desirous ofcontributing knowledge towards the life history of this cestode. Asa result of these researches it is now a well established fact that severalarthropods belonging to the Lepidoptera, Dermaptera, Coleoptera, Siphonaptera and Myriapoda can function as intermediate hosts althoughthis wide range of vectors is somewhat unusual.

(1) The reactions of Dorylaimus under ordinary conditions of life are noted, especially its mode of progression and its burrowing habit.

(2) Some experiments were carried out with a view to finding out what physical and chemical stimuli are responsible for bringing about these reactions.

(3) The possibility of hydrotropism, thermotropism, geotropism, stereotropism, heliotropism and chemotropism are considered.

(4) The conclusion to be drawn from the data is, that taken on the whole, eelworms do not exhibit well marked tropic responses except in the case of stereotropism. It is obvious here, however, that they do everything in their power to put their body surface in contact with some solid object. This need explains why the worms are always found in the interstices of the zoogloeal film round the clinker. No other tropic response is needed to explain this habitat.

In the experiments carried out by Nishigori (1925) and Saito (1925) on the life-history of Hepaticola hepatica it was shewn that this parasite does not reach maturity when a rabbit is artificially infected with embryonated eggs. It is true that the worms shewed some development, but after a time they disappeared leaving only nodules of connective tissue. In view of these results it may be of interest to record a case, observed by the writer where a rabbit carried a natural infection.

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.