In 1908 intestinal parasites of man were described by Bohne and Prowazek. The authors considered them to be cysts of Trichomonas hominis. The parasites consist of a highly refractile spherical body, staining yellow or yellowish brown with iodine and pale grey or black with iron haematoxylin; this sphere is surrounded by a narrow plasmatic layer, containing the nuclei. Bensen (1910) gave a detailed description of these bodies, with stages of autogamy, and considered them also to be cysts of Trichomonas. Prowazek (1911) did not subsequently change his opinion regarding the systematic position of these bodies and James (1914) confirmed Prowazek's views by stating that cats infected with the same bodies showed Trichomonas in their stools.

Le présent ouvrage est consacré à la caractéristique de quelques espèces de Nématodes d'oiseaux, trouvés sur le territoire de l'Empire de Russie. La plupart des formes décrites ici m'ont été gracieusement données à étudier par le Professeur de l'Académic Impériale Militaire de Médecine N. A. Cholodkowski, et je saisis l'occasion de lui exprimer ma plus sincère gratitude.

The clearing action of mosquito larvae in turbid water and their scarcity or absence in clean water, is an old-established popular belief in mosquito ridden districts of both the old and new world. If the presence of certain species of Anopheles larvae in clear running water, where they doubtless feed on algae, be excepted, it is probable that this general observation is in the main correct. The fact that numbers of mosquito larvae are frequently present in the small collections of clear water which occur in the cut ends of bamboos, the axils of leaves, or the smaller rock or root pools, is an apparent but not a real contradiction of the correctness of this popular belief, because in these instances one of two possibilities may have occurred. Either the large number of dormant eggs which hatched when rain first filled the receptacle was sufficient to check and control bacterial or yeast development from the start, or, as is more likely in the case of root or rock pools, the turbidity due to bacteria or yeasts had been rapidly cleared as the rapacity of the quickly growing larvae increased beyond the source of nutriment.

The claim made for the first time by Barrett and Smith (1914a) some two years and a half ago, that the causative agent of Pyorrhoea Alveolaris is the Entamoeba gingivalis led the writers to enquire into the question; the results of which enquiry are set forth in the following paper.

Several years ago I collected cestodes parasitic in Selachians found in Japanese waters. Most of them were mature and well preserved. The specimens are referable to ten species, of which five belong to known species and five are new to science. Since the published descriptions of the known species are not entirely in accord with my observations, and some of the species are not satisfactorily described anatomically, I shall re-describe the known forms briefly in the following pages.

This paper is written primarily with the intention of publishing descriptions of two new genera of Nycteribiidae, together with some notes relating to certain already known forms of that family. But it also includes an account of some recent work (not my own), which for the first time gives us a detailed insight into the habits of these bizarre creatures. This latter side of the subject will be considered first.