Whilst engaged on protozoological investigations of dysentery and allied diseases in Mesopotamia I had the opportunity of examining the stools of a large number of hospital patients, both British and Indian, and of noting the presence of worm ova as well as protozoan parasites.

Having during the last few years been particularly interested in the Nematode parasites of horses and donkeys I was very pleased to find a tube containing Strongyles from the zebra among some material recently forwarded to me by Professor G. H. F. Nuttall, F.R.S. These worms formed part of a collection of Helminths from Nairobi, British East Africa, which had been sent for identification by Mr R. Eustace Montgomery, Director of the Nairobi Veterinary Pathological Laboratory.

1. A parasitic spiral organism averaging 4 to 8μ long, with regular, closely set spirals about 0·75μ broad, has been found in the stomach in eight cats, none of which showed any obvious signs of gastric disturbance. The organisms occurred in the lumina of ducts and glands throughout the stomach, and also within the oxyntic cells. They were not seen in any part of the intestines except the very beginning of the duodenum, or in any other organ.

2. They are extremely active, and are readily stained by aniline dyes.

3. The mode of passage from one animal to another is not known, but food and faeces may be eliminated as possible sources of infection.

Papio cynocephalus from French Guinea frequently harbours Loa papionis n.sp. The intermediate host is unknown. The larvae, in contradistinction to those of the human parasite Loa loa, show no diurnal periodicity.

The occurrence of bacterial disease in adult L. papionis would seem to be a novelty; at any rate I could find no mention of diseased filariae in the literature.

In so far as the biology of Microloa loa is concerned, I am inclined to doubt the correctness of the opinions expressed by Rodenwalt and Fülleborn concerning the structures they term “executory and genital cells”: the current hypotheses concerning the significance of these structures and of the “central viscus,” clearly need revision. Manson's “buccal apparatus” would seem to be nothing more than an optical illusion, while the “neck” or “shoulder” described by the older observers as existing in adult L. loa after fixation, was evidently due to imperfect technique.

I have drawn attention to the desirability of standardising the technicalities which are such essential preliminaries to the accurate mensuration of micro-filariae, and have suggested a method which has certain advantages over those at present in use.

Concerning the pathology of Loa infection, evidence both of the traumatic and toxic action of L. papionis on baboons, was obtained; moreover these parasites seemed definitely toxic for guineapigs, although the single experiment performed needs confirmation. The available evidence favours the supposition that adult baboons from an infected area possess a high degree of immunity both against L. papionis toxaemia and against reinfection by these parasites; but whether their serum is of therapeutic value for human beings infected with L. loa, requires further investigation.

The object of this paper is to draw attention to certain grave sources of error underlying the present mode of differentiating Anoplura and more especially species of the sub-order Siphunculata. I am unable to say if the criticisms herewith advanced apply equally to the methods employed in differentiating members of the sub-order Mallophaga, because I am not familiar with the latter group, but the two sub-orders mentioned are in many respects so closely allied that it appears difficult to avoid the suspicion that the considerations herein contained may apply equally in both cases.

The host of this gregarine is the larva of a Ceratopogonid: Dasyhelea obscura Winnertz, which, as I have previously mentioned, lives in the decomposed sap filling the infected wounds of the Elm and Horse-chestnut trees in Cambridge (at Newnham and along the Queen's Road). The parasitised larvae were found late in the season, about the end of September, they were all young and never heavily infected, containing from three to eight and exceptionally twelve parasites in different developmental stages. The gregarine seems to be rare as among several hundred of these larvae examined only twelve yielded this interesting parasite.

It has long been known that ticks possess spermatozoa that differ considerably from the typical flagellate form. In similar cases science has always attempted to trace the aberrant type back to the normal with a view to identifying its constituent parts. Many forms, even those which at first sight appear incapable of being compared with the normal, have recently been thoroughly analysed in this manner. On the other hand there occur several types of spermium whose parts it is impossible to compare with those of the normal type and in these instances all that can be done is to identify the elements that take part in the fertilization, viz. the nucleus and centrosome.

The species herein described both belong to the family Menoponidae. One of these species, collected by me from a Waxbill (a passerine bird) at Onderstepoort, Pretoria, belongs to the genus Machaerilaemus Harrison, the other, taken from a Sandgrouse in the Rustenburg District, Transvaal, by Mr Powell, together with specimens of a species of Degeeriella, I am placing in a new genus, for which I propose the name Neomenopon. These two new species are extremely interesting, in that they both possess a chitinous framework extending backwards from the anterior margin of the head for the support of the mandibles, a structure previously only known to occur in the genus Eomenopon Harrison, which was established partly on account of this structure. A similar structure, however, also occurs in a small unidentified species of Menopon taken from a Little Banded Goshawk (Astur polyzonoides) at Onderstepoort. This species may eventually prove to be sufficiently distinct in other details from the type of Menopon to warrant the founding of a new genus for its reception.

During the summer months in Mesopotamia body-lice become extremely scarce on man, so much so that it may be difficult to find them even on men who are renowned for lousiness at other seasons of the year. When the nights become cold, as they often do rather suddenly towards the end of November, lice rapidly become numerous, this coinciding with the reissue of winter under-linen which has been stored through the summer in Ordnance dumps.