In 1924, Morgan visited South Lincolnshire to investigate the part played by the potato-root eelworm (Heterodera schachtii) in the serious failure of the local potato crop: a note on the investigation appears in this Journal (1925, p. 185). A second visit was made in 1925, as a result of which certain conclusions regarding manuring and the rotation of crops were put forward (this Journal, 1926, p. 49). Towards the end of 1925 the second writer (Peters) made a hurried survey with the object of seeking a possible correlation between the distribution of eelworm cysts and the hydrogen ion concentration of the soil. Such a correlation was actually demonstrated (this Journal, 1926, p. 87) in the case of a selected field for which Morgan had complete data of cyst-counts. The question thus arose as to whether any clear correlations should be shown to exist between the three factors: concentration of cysts, pathological condition of the crop, and reaction of the soil. In other words, was the eelworm associated with the damage? and was it controlled (and therefore controllable) by the effective acidity of the soil? To decide these questions might be a matter of considerable importance, particularly if the eelworm was found to be responsible for the damage, for affirmative answers would open the way to effective treatment, by the adequate liming of soils for instance.

Owing to the failure of the potato crops in South Lincolnshire in areas where the eelworm Heterodera schachtii was known to occur, investigations were undertaken by this Institute to determine to what extent the nematode was responsible for the losses incurred, and to discover some method for its control. This work was begun by Dr. D. O. Morgan in the autumn of 1924. In order to gain a general knowledge of the natural conditions under which the nematode occured, and to obtain some indication of the most promising lines on which fundamental research might be carried out, extensive field observations were made. By this meand much data was accumulated which has been of great service in the carrying out of later laboratory adn field studies.

The Potato Testing Station at Ormskirk, a branch of the National Institute of Agricultural Botany, has during the past season, been found to include considerable areas of land heavily infested with the eelworm Heterodera schachtii. This discovery was made subsequent to the failure of some of the potato crops, which, in the course of the normal rotation practised at the station, happened last season to be grown on the affected areas.

In 1927 Fairley Described in the Medical Journal of Australia an Intradermal Reaction in Human Schistosomiasis, Using as Antigen the Dried Powdered Livers of Snails (Planorbis Exustus), Infested with the Cercaria of Schistosoma Spindalis of the Goat, Dissolved in Saline. The standard dose adopted was 0·25 cc. of an 0·5 per cent, extract prepared from the dried powder, ground up in a mortar with 50 ccs. of normal saline solution (0·85%) and the resulting mixture thoroughly shaken by hand. It was then incubated for one hour at 37° C. Subsequently the extract was centrifuged, the supernatant fluid pipetted off and filtered through a Seitz filter (size 3) attached to a water pump. The filtrate, consisting of a clear coloured fluid is put up in ampoules of 0·5 cc. each and stored in an ice-chest.

May I say, in the first place, how highly honoured I am by the invitation of the Royal Faculty of Physicians and Surgeons of the City in which I received my early medical training to give the sixth Finlayson Memorial Lecture.