In several previous publications by the present writer reference has been made to the relation between the root excretions of plants and the bionomics of the eelworm Heterodera schachtii. Amongst these is a short preliminary note on the significance of the root excretions of certain grasses as a possible means of controlling the nematode. The experiments referred to in this paper having been continued and extended, and the favourable results of the first year's field work having been maintained, a more detailed account of the researches seems to be justified, although the field experiments are still in progress and many aspects of the problem which require laboratory investigation are as yet comparatively untouched. As previously indicated, of the two main lines, chemical and biological, along which investigations must be pursued for a full understanding of the relationship between the reactions of the nematode and the stimulus of the root excretions, the chemical is the more fundamental, and until further work has been carried out from this standpoint much of the biological work is necessarily of an empirical character. It is, however, on purely biological lines that the greatest progress has so far been achieved, and it is with this side of the work solely that the present paper deals.

More than twenty years ago Schwartz (1911) described a disease of cultivated violets associated with eelworm attack. The plants were obtained from gardens at Greiz and Kreuznach in Germany and in all cases had distinct gall-like swellings at the bases of the leaf-stalks. As the disease progressed the leaves became smaller and smaller and the leaf-stalks shorter until, finally, an irregular, walnut-sized gall was produced the surface of which was covered with abortive buds. Schwartz drew attention to the similarity presented by such plants to the “cauliflower” condition in strawberry plants associated with the presence of Aphelenchoides fragariae. Goffart (1930) mentioned the fact that the disease persisted for a time in Germany; being reported in 1910–12 and 1915–17 but had not been recorded again up to 1930.

This paper embodies certain experiments on control of the nematode Aphelenchoides ritzema-bosi Schwartz, 1911, on chrysanthemums, and were started in September 1930 at the request of several commercial chrysanthemum growers in Staffordshire and Warwickshire.

It is only within the last few years that the various species of Bulbous Irises have been recognised as host of Anguillulina dipsaci. Despite the comparative paucity of information on the matter there is evidence of the likelihood of infestations becoming serious in the immediate future. It may, therefore, be of value to place on record such information as is at present available.

The question of helminth parasitism in British goats appears to have had little or no attention paid to it. This is somewhat surprising when one considers the fairly large number of goats which must be present in this country and, although no annual statistics as to the number of goats in Britain are available, Holmes Pegler (1929) observes that early in 1925 the Ministry of Agriculture, assisted by the British Goat Society, obtained returns of the number of goats in England and Wales which was set down as, roughly, 60,000. Similarly little definite data is available on the frequency and intensity with which these animals are infected by helminths in different localities. In this paper an attempt is made to supplement the meagre data relative to these conditions.

1. The occurrence of Syngamus nasicola Linstow, 1899, in sheep, cattle and goats in the West Indies is recorded.

2. The species is re-described, on the basis of West Indian material and cotypes from deer and goat.

3. The species is contrasted with S. laryngeus Railliet, 1899, with which it has affinities and has hitherto been thought to be identical.

4. Special emphasis is laid on the use of the internal structure of the buccal capsule in differentiating the two species.

5. Syngamus kingi is compared with S. nasicola and it is concluded that the two species are identical, in which case S. kingi becomes a synonym of S. nasicola.