In an article on “The Longevity of Diphyllobothrium latum” published in 1935 in the “Recueil des Travaux dédié au 25-me Anniversaire Scientifique du Professeur Eugène Paviosky 1909−1934”, it is suggested that present day conceptions regarding the longevity of this parasite are erroneous and that multiple successive infections are frequently attributed to a single long-lived specimen. Ward gives a detailed review and analysis of the evidence hitherto published both in general works and special monographs and cites as specially important the history of the occurrence of this species on the North American continent. He points out that the age of the parasite is regularly based on the statement that the host had not been in an infected region for the period indicated. To this statement, Ward puts forward the objections that the distribution of the parasite and the natural occurrence of plerocercoid carrying fish are far more extensive than was formerly suspected and, further, that infected fish are distributed commercially as food to regions far outside their natural area of distribution. He also refers to certain records which seem to indicate that there is a “period of inactivity” during the adult life of the parasite and suggests that its alleged occurrence throws doubt upon the supposed longevity of the parasite. In support of this contention, he cites, as a typical instance, a case of human infection with Diphyllobothrium latum reported by me (Leiper, 1928) as a “cryptic infection”; regarding which he erroneously states that I believed was “latent” for 5 years.

The material forming the basis of the following account was collected from a ruby-crested humming bird, Chrysolampis mosquitus, a native of Brazil. This bird died in the gardens of the Zoological Society of London and the parasites were forwarded for identification to Dr. R. T. Leiper, F.R.S., of the London School of Hygiene and Tropical Medicine.

Beef measles is prevalent in many parts of the world. The two most important factors which allow the dissemination of the disease are, firstly, the insanitary methods of the disposal of human excreta, and secondly, the habit of eating beef raw or almost raw. To eradicate beef measles and Taenia saginata from a country where the inhabitants are eaters of raw beef, would be a costly and difficult undertaking. The fact that Taenia saginata infestation of man is a comparatively trivial disease and, therefore, does not induce many infested persons to seek treatment, is another difficulty in preventing its dissemination. Of 90 cases that came to our notice, 65 did so in reply to an offer of £5 reward for a complete tapeworm (1), and, although the average duration of infestation of these cases was 13 years, many had never previously sought treatment. We consider there are two main methods of preventing bovine cysticercosis. The first is to immunize the cattle against the disease, and the second is to prevent cattle from having access to Taenia saginata eggs. With regard to the second method, if means are undertaken to prevent Taenia saginaia ova from gaining access to a pasture previously contaminated with them, the problem still remains of getting rid of the ova which are already present. This paper considers the latter problem, and is specially applicable to farms irrigated with human sewage. It has been suggested that pastures may be ridded of Taenia saginata eggs by grazing sheep.

Two new species of Avitellina, A. woodlandi and A. tatia, have been described and separated from the allied species of the genus. Both these species are remarkable for having cirrus sac longer than vulva.

Additional data are provided in regard to the structure of the species A. sudanea, A. lahorea and A. chalmersi.

The development of the female genitalia of A. chalmersi, which may be regarded as typical of the genus, has been given in detail for the first time.

New observations on the development of the inner column of testes in A. sudanea are made.

A review of the existing species of Avitellina has been taken and a key to all the known species of the genus has been given.

The material of Eurytrema pancreaticum from Hyderabad (Deccan) was examined and found to agree with the material of this species from China and Japan, described by Looss (1907) except in the case of cirrus sac which terminates anterior to ventral sucker.

Numerous specimens of the variety of E. pancreaticum with deeply lobed testes from the pancreatic ducts of a cow in Bengal were examined and it is found that the smaller and the larger forms belong to the same species. Variations occurring in several organs of this variety have been recorded.

A discussion on the existing species of Eurytrema has been evoked and these have been grouped under five subgenera, four of which being new ones.

The species E. ovis, E. robustum and E. cuyabai are considered to be synonyms of E. pancreaticum, E. lubens and E. intermedium respectively.

The species E. parvum Travassos, 1916 being a homonym the name E. travassosi has been suggested for it.

Paradistomum moghei n.sp. has been described and separated from the existing species of Paradistomum.

Mesoccelium leiperi n.sp. has been described and separated from the existing species of Mesocalium.

Mesoccelium sociale has been recorded from Rana tigrina and measurements of some of its organs are given.