In a previous publication the morphological characters of a strain of H. schachtii specialised on the potato in Lincolnshire were discussed. The size and shape of the brown cysts, size of the eggs and first stage larvæ and the general characters of the adult males of this strain were compared with those of a strain attacking potatoes in Rostock, Mecklenburg, for which the specific name H. rostochiensis was suggested by Wollenweber 1923.

Considerable dimensional variations were found to exist in the Lincolnshire strain, and a study of the literature on the morphological characters of H. schachtii specialised on sugar-beet and oats, showed equally wide divergencies between the findings of different workers. A certain amount of preserved material of infected roots of beet and oats being available to the writer, as many developmental stages as possible were extracted from these, on which similar morphological studies were carried out. Thus a fairly complete comparative survey of H. schachtii specialised on beet, oats and potatoes was completed, and the morphological variations between the strains were found to be insufficient to justify the separation of the strain specialised on potato from those on beet and oats. The name H. rostochicnsis was, therefore, deemed a synonym for H. schachtii.

Anguillulina has been revived by Baylis and Daubney (1926) as the correct generic name for those worms which for many years have been considered as belonging to the genus Tylenchus, at least by most specialists on nematodes and plant-pathologists. Gervais and van Beneden on pp. 101 and 102 of the second volume of their work Zoologie Médicale, published in 1859, gave a brief account of the eelworm parasite of wheat causing “purples” or “cockles” and that found by Kuhn in 1858 in the heads of the fuller's thistle, teasle, both of which they designate as Anguillulines (Anguillulina) as follows:—Anguillilina tritici and Anguillulina dipsaci.

It may be pointed out, in passing, that they were not consistent in the use of the word, for at the end of the description of A. dipsaci they spell it as Anguillula not Anguillulina. This may, however, perhaps be regarded as an unintentional slip or a printer's error. Bastian's paper in which first the name Tyleenchus and then Tylenchus is applied to members of this genus appeared in 1865 and he designated Tylenchus davainii as type species of the genus in a letter to Stiles dated March 22nd, 1904, vide Stiles and Hassall (1905).

The plant parasitic nematode, Tylenchus dipsaci Kühn, commonly known as the stem eelworm, or alternatively when occurring in narcissus, the bulb eelworm, is a major pest of a wide range of cultivated plants. Accurate knowledge concerning the detailed life-history of the nematode is still of limited extent, despite the large numbers of workers who, throughout Europe and more recently North America, have devoted much time to a study of the subject. In particular it is clear that much remains to be learned concerning the “biologic strain” theory. Investigators, probably without exception, agree that a large number of, so-called, biologic strains of the worm occur. Each of these strains, while morphologically identical with the others, appears to be restricted more or less rigidly to a particular species of host plant.

Muellerius capillaris was first described by Mueller in 1889 who placed it in the genus Pseudalius; it was transferred in 1907 by Railliet and Henry to their new genus Synthetocaulus. In 1927, Cameron, in his review of the family Protostrongylidæ Leiper, 1926, created the genus Muellerius to include this species; a description of this parasite together with figures of the adult and the larval stage commonly met with in the lungs and droppings of sheep and goats, is included in his paper.

M. capillaris inhabits the bronchioles and alveoli of the lungs of sheep and goats but is probably more often observed in the connective tissue of the lungs where it forms nodules of varying sizes. In heavy infestations these nodules are so close together that they appear as large greyish patches on the surface of the lung. The nodules eventually become calcified.

The vast majority of the helminthic parasites of man are represented among those animals which are in close contact with man, either by the same species or at least, by closely related forms. A very noticeable exception is Enterobius vermicularis. Possibly owing to its special life-history, it has become highly specialised for its human host and to find its closest relations, it is necessary to examine the forms found in primates.

The object of this paper is accordingly to systematise our knowledge of the oxyurid worms found in this group.

As Enterobius vermicularis is the most important of these, it has been found desirable to briefly re-describe its anatomy, followed by that of the related species, in apes, in monkeys and other primates.