In the spring of 1932 an experiment was set up to observe the effects of intensive grazing, by the heavy stocking of a pasture, on the worm infestation of animals, and to arrive at some estimation of the consequences of modern grazing practices. These observations covered a period of one year and the results obtained from the experiment, which was carried out by one of us, have been put forward in an earlier paper (Morgan, 1933). Some conclusions were drawn from the work but these were considered as purely provisional owing to the small scale of the experiment and to the observations covering the comparatively short period of a year. It was pointed out that the effects of overstocking would not become evident until pastures had been under a system of rotational grazing for many seasons and when the concentration of helminth ova and larvae had reached a very high level. With this in mind it was decided to proceed with observations on the effects of heavy stocking on the worm burden by setting up a fresh experiment running on lines similar to that already described but using, in places of the goats in the 1932–33 work, one-year old sheep, as it was thought that this type of stock would ensure a closer cropping on the experimental plots.

Twenty-five species of Nematode have been found to be present in sheep in Manawatu district. The species of greatest economic importance were found to be in most cases of importance in other temperate climates.

In the cases of certain species, saturation of Manawatu district has not yet occurred, e.g., in the cases of Cooperia oncophora, C. punctata and Ostertagia ostertagi.

The countries of origin of the foundation stock have limited the number of species. Most of the importations have been made from Britain and Australia.

As few nematodes of the sheep require intermediate hosts, their entrance to a new country, New Zealand, has not been prevented to any extent on this ground. Muellerius capillaris has been able to survive on account of the abundance of its normal host, which has been introduced also.

The climate of Manawatu is such that the extremes of summer and winter are not severe enough to exert complete control on the various species. Infective stages are well able to survive these less favourable periods. The climate is sufficiently equable to enable out of door pasturing throughout the year, so that in the cases of most species of nematoda infection it is possible also throughout the year.

The farming systems in vogue involve almost solely the use of permanent pasture which is mostly of high carrying capacity. This enables concentration of stock and in conjunction with continuous grazing throughout the year, enables the excessive multiplication of the various species of nematodes.

The prominence placed on the fat lamb industry means that much attention is devoted to the raising of a population susceptible to worm infection.

A prevailing practice is to introduce culls from the surrounding hill districts for purposes of fattening, and sheep from the Hawke's Bay district in time of drought. There is consequently a continual introduction of parasites in these animals.

Cattle are the chief reservoir hosts of nematodes of sheep in Manawatu district. These occur in large numbers in the district and frequently dairying is combined with sheep farming, so that they become important sources of infection to sheep in respect to some species of worm, e.g., Cooperia oncophora, C. punctata and Ostertagia ostertagi.

It would seem that the tendency in the district is towards the increasing of the carrying capacity of pasture. This should result in the multiplication of parasites, particularly Nematodes, to a greater extent than has been the case.

The general outlines of the life history of Taenia pisiformis (Bloch 1780) in the dog and the rabbit have long been well known. The following reinvestigation of the early stages of the development of Cysticercus pisiformis in experimental rabbits was undertaken with the primary objective of checking or refuting the “division” of the Cysticercus described by Moniez in his classical monograph on the Cysticerci, published in 1880.

The present work forms a continuation of a survey undertaken three years ago, with a view to elucidating the nemic parasites commonly found in fishes of Canadian waters. These species have proved to be largely undescribed, and old species have always offered some new points of interest. The greatest difficulty has been encountered with the literature, much of which was difficult of access. Only those papers which have a definite bearing on the forms studied, and convey some pertinent information, are included in the appended bibliography.

Yakusu lies on the North bank of the river Congo twelve miles below Stanleyville and the termination of the rapids of Stanley Falls. One of largest tributaries, the Lindi, joins the main stream just above the settlement.

Venkatarayan (1932) gave a short account of the occurrence of galls on Andropogon pertusus Willd., a common pasture grass of South India. He described the appearance of the galls, their distribution on the plant, the symptoms to which they give rise and established the fact that the nematode causing them is a species of Tylenchus to which, however, he did not give a specific name. He pointed out that there were no earlier records of the occurrence in India of galls on grass or cereals due to nematodes apart from those caused by Anguillulina tritici in the ears of wheat.