The coloration of Amblyomma hebraeum, A. gemma, Dermacentor venustus, D. variabilis and D. reticulatus niveus, as seen in living examples, is depicted for the first time, and the desirability of recording the colours of ornate ticks when alive is indicated.

A remarkable change in colour in living specimens of A. hebraeum is described and figured, this change taking place after a prolonged sojourn (74–141 days) upon the host. Such a colour change has not hitherto been observed in ticks. The difference in colour is seen in dead dried specimens but is not appreciable in those preserved in alcohol.

Since the immature stages of ornate ticks are inornate, and the colours change in adults of some species during prolonged periods of parasitism, it is evident that the coloration in adults must depend upon the accumulated products of metabolism beneath the chitinous exoskeleton, the regional distribution of colour depending upon special metabolic functions taking place in corresponding parts of the tick. The ornamental colour-producing layer can be scraped away from the underside of the scutum in most ornate ticks and it is removable from such ticks by the use of caustic potash.

The whitish or creamy coloration that is so characteristic of most species of Dermacentor and the three ornate species of Rhipicephalus that are known to science, appears on the other hand to depend largely upon inclusions or structural changes within the chitin itself, whence the persistence of the creaminess seen by reflected light in the caustic-treated ticks. Similar, but less distinct, appearances may be seen in ticks belonging to other genera. Dermacentor rhinocerotis, which does not exhibit creamy coloration but only dull yellowish spots when dry, is totally decolorized by caustic potash, whilst contrary to most species of its genus it shows metallic coloration in well-preserved specimens in alcohol.

The examination of caustic-treated specimens was carried out upon 31 species of ornate ticks, i.e. Dermacentor (8), Rhipicephalus (3), Amblyomma (15), Aponomma (4) and Hyalomma (1 species).

The coloration and creamy ornamentation, herein distinguished, appear to be confined to the thinner portions of the exoskeleton. That the characteristic dark markings correspond to thicker and more darkly chitinised portions of the scutum is demonstrable by dissections, caustic-treated, or sectioned specimens; this being especially evident for instance in Amblyomma. The orange spot on the scutum of A. splendidum offers an exception.

The optical and chemical study of coloration in ticks deserves further investigation.

Amputation experiments upon immature stages of Argas persicus (Oken 1818), Amblyomma hebraeum Koch 1844, and Hyalomma aegyptium (Linnaeus 1746) show that the mouthparts and legs of these ticks may be more or less regenerated when mutilated shortly after the ticks have abandoned the host in a fully engorged condition.

During the last few years our knowledge of the Sclerostome parasites of the horse has been greatly augmented, the nematodes of the donkey have not however received attention since 1901, the date of publication of Looss' famous monograph on the Sclerostomes of the Equidae.

In 1851, Bilharz (1852) first discovered paired adult trematode worms originally named after him in the portal system of an Egyptian fellah. Subsequently, investigations of the deposits of ova in excreta were made, but numerous attempts by Cobbold, Sonsino, Lortet and Vialleton (1894) and others, to unravel the life history of the parasite, failed. Looss (1896), appreciating that the digenetic trematodes must necessarily pass through a molluscan intermediary, dissected many species of snails collected from the fresh-water canals around Cairo. He failed to find the cercariae of bilharzia, and discarded the hypothesis of an intermediate molluscan host. As, however, the miracidium of Schistosomum haematobium contained germinal cells within its body cavity, it must, naturally, he argued, have been destined to produce sporocysts at some stage of its life cycle. In view of this, Looss evolved the hypothesis that man acted simultaneously as the intermediary, as well as the definitive host of this parasite.

The following observations are the result of two years' examination of the stools of patients invalided to and stationed in Malta. The patients may be roughly divided for convenience into four groups:

(1) Troops sent straight from the Salonika Hospitals to Malta. This section comprised the bulk of the total number of troops examined, and included a few men from Egypt.

(2) Garrison Troops—some not patients—including both British and Maltese. With these are included a few British and Maltese Civilians,. connected in some way or another with the Army.

(3) Troops on their way out from England or France. These were mostly Indians and Chinese, who were put off transport at Malta owing to disability.

(4) Prisoners of War interned in Malta.

The genus Monospora (= Monosporella renamed) was founded by Metschnikoff in 1884 to designate a parasitic fungus which he discovered in Daphnia magna. This monocellular fungus, of which he described only one species, Monospora bicuspidata, lives free in the body cavity of its host, where it multiplies actively by budding in a yeast-like manner (Fig. I, 1, 2, 3).

Maupasella nova Cépède was discovered by Maupas (1877) in the alimentary canal of an Algerian earth-worm and subsequently described by Cépède (1910). As was well remarked by the latter author, this ciliate varies much in size and in form, long specimens measuring 80–95 by 25μ., and short ones only 50–75 by 27–47μ. The essential characters of Maupasella are: (1) the presence of an anterior fixing apparatus in the form of a conical process derived from thickened ectoplasm, (2) an elongated ribbon-like macronucleus, (3) irregularly disposed contractile vacuoles, and (4) dense ciliation. Moreover, the micronucleus (PI. VI, fig. 18 and m in all the other figures), which is often difficult to see, is spindle-shaped, with its axis parallel to that of the ciliate's body, strangulated in the middle and with the chromatin condensed into a disc lying in the strangulated portion of the spindle.