A simple apparatus is described in which can be measured the vertical migration of Heterodera rostochiensis larvae in soil and in the presence of the host plant. The migrations upwards and downwards are comparable in extent, but can be inhibited by water-logged soil and greatly reduced if the cysts are exposed to insolation under glass when near the soil surface. In the layer furthermost from the inoculum (8 to 10 inches away), either no cysts are formed or their number constitutes a very small proportion of the total: a fraction of one per cent.

By growing potatoes in infested soil in sectional wooden boxes, changes in the population of potato root eelworm have been observed at 5, 9, 13 and 19 weeks after planting, and at 5 two-inch levels in the soil. Results show that most of the increase in population occurred during the last 6 weeks of the experiment and that the normal population changes proceeded more slowly in the topmost level, leading to a lower final population in that level.

1. When potatoes are planted in eelworm infested land, the root diffusate produced results in 70—80 per cent, of the larvae emerging from the cysts in the first 4—5 weeks of growth and this effect is shown up to a distance of 6 in. from the root centre.

2. Moderate or heavy soil infestations of potato root eelworm result in a considerable root invasion prior to potatoes breaking through; several thousand cysts can result from this early attack and can cause severe dislocation of the young root.

This highly distinctive worm was collected in Honde, Southern Rhodesia, on two separate occasions, from hosts designated “house rat” and “native granary rat” which the writer understands could readily be one and the same, since houses and granaries in these areas are built in fairly close proximity. If, however, it is assumed that these buildings are at a distance from each other, it is possible that two different genera and species are concerned; and if such is the case, the “granary” rat might possibly be a field rat. It is regretted that the identification of the host cannot be more explicit.

(1) A survey was made of the trematode and nematode parasites of Apodemus sylvaticus, Clethrionomys glareolus and Sorex araneus from the islands of Raasay, Ulva and Scalpay.

(2) The following species have been recorded:—

A. sylvaticus:

Trematodes—

Lyperosomum villa

Brachylaemus recurvum

Nematodes—

Capillaria muris-sylvatici

Heligmosomum glareoli*

Syphacia stroma

In reviewing the literature on helminthology one finds that a great deal of attention has been given to the study of the physiology of parasites. Investigations of such a nature are valuable, in that they enable one to approach the problem of anthelmintic treatment in a scientific manner. Most of the early work that was carried out on lungworms in general was concerned either with their life histories or with their morphology, and little work has been done on their physiological characteristics.

Intensive cropping on a commercial scale as practised on fertile land in Europe is hitherto unknown in the Gold Coast apart from the growing of cocoa trees in a wide belt stretching from east to west across the central region of the country. In general, the method of farming is exceedingly primitive, being largely shifting cultivation, that is, the bush is partially cleared and the land is then cultivated by hand-hoes and cropped for a period of three or four years. Normally, no manure of any kind, either organic or inorganic, is applied and the land at the end of this period is allowed to revert to bush. New ground is brought into cultivation in its place, only to be allowed when virtually exhausted of readily available plant food to return to its natural, jungle condition.

1. Fasciola indica n. sp. from goats, cattle and buffaloes in Bihar is described and differentiated from F. hepatica and F. gigantica.

2. Specimens of Fasciola from Assam (cattle and buffaloes), Rangoon (cattle), Singapore (pig) were examined and identified as F. indica.

3. F. hepatica is further differentiated from F. gigantica on the basis of the cuticular armature and the disposition of the intestinal branches.

In summarising, therefore, we conclude that a tendency to become dormant during the larval stage, which is so characteristic a feature of the free-living larvae of parasitic nematodes and is an essential requirement in their use of intermediate hosts is not an uncommon occurrence during their life in the final host. Its purpose in each instance is essentially the same, i.e. to carry it through a period in which the environment is unsuited to development; on the ground, for instance, where it waits for a suitable host, as a parasite of an intermediate host, where it waits for a suitable final host, or in a resistant final host where inhibited development serves the parasite in enabling it to wait until some depression of the host's state of resistance allows it to grow to maturity.