Many writers having observed that cases of acute rheumatism are not distributed evenly throughout the year, much study has been devoted to the possible relationship between these variations and meteorological conditions.

Most towns augment their water supply from wells, and in South Africa, where the rivers are said to run underground, Johannesburg is no exception.

Its chief supply is from deep wells in the dolomite some 20 miles to the south-west of the town, but one of the suburbs—Parktown—is not connected to the main supply, but at present draws its water from two wells (the property of the Rand Water Board) which will be subsequently referred to as No. 1 and No. 2, sunk in the shales of the upper Witwatersrand beds. From here the water is pumped to two Water Towers situated at the highest point of the suburb from whence it is distributed by gravitation. For various reasons, the Rand Water Board had decided on replacing the pumping machinery at these wells by electrically driven gear, and advantage was to be taken of the change to properly line and deepen the wells by a steel bore-hole.

Weichselbaum (1887) first described his Diplococcus intracellularis meningitidis (meningococcus) as having been cultivated within a few hours after death from the brain or meninges of six cases of acute cerebro-spinal meningitis. These cases occurred during the years 1885—1887 at Vienna, when no regular epidemic existed. Cases had however occurred from time to time, and there was an epidemic in part of Lower Austria in 1886. The youngest case was 14 years old. He described the micrococcus as being of a wide gonococcus-like shape, occurring in pairs or fours, not in chains, negative to Gram's stain. It failed to grow at 20° C., but grew well on agar at 37° C. almost exclusively on the surface. The growth was viscid, the colonies were often confluent and appeared finely granular when slightly magnified. The organisms required sub-culture every few days to ensure success, were easily killed by drying, and showed very little growth in broth.

1. Antibodies in general are absorbed very slowly from the peritoneal cavity in lower animals, and from the subcutaneous tissues in man and animals. Absorption from the latter is not complete until at least 2—3 days have elapsed.

2. The amount of antibody present at any one time in the general circulation after intraperitoneal or subcutaneous injection is very much less than the amount injected.

3. Clinically, in urgent cases of disease, to inject antibodies subcutaneously is not only to lose 2—3 days' time before the full action can be obtained but to reduce the amount of action that the dose injected can have.

4. By intravenous injection the maximum amount of action is obtained at once.

The whole of the experiments recorded in this paper were made in the Statens Serum-Institut at Copenhagen, where every possible facility was given me for the carrying out of this research. To Dr Thorvald Madsen I desire to express my thanks not only for his unvarying kindliness and courtesy, but also for suggestions and assistance constantly given. I am pleased to have this opportunity of expressing my indebtedness to him.

It is well known that when milk is allowed to sour, the rise in acidity is not directly proportional to the increase in the number of acid-forming bacteria. There is a distinct phase in the process during which numerical increase of these organisms takes place, accompanied only by slight acid production, after which the acidity rises very rapidly to a maximum.

In the present paper we describe the results of further investigations on the life-history of Piroplasma canis in the blood of the dog. In our last paper (x. 1906) we described and figured the movements of the parasite and the mode of multiplication in the dog's blood, and since that time we have confirmed most of our previous observations, and added further facts. The technique of these examinations was fully explained in that paper (p. 604), and it is only necessary to state here that all our later observations on living blood have been made at a temperature of 35°—40°C. The drops of blood were mounted on clean glass slides and cover-glasses kept at this temperature, and were placed as rapidly as possible on the stage of a microscope kept at a similar temperature in a Nuttall's thermostat and examined under a oil immersion lens. In fact we have endeavoured to make our observations in such a manner that the blood should be altered as little as possible.

The investigations which form the subject of this paper were undertaken at the Pasteur Institute, on the suggestion of M. Mesnil. It is a pleasure to acknowledge my great indebtedness to M. Mesnil for the help and advice he so willingly rendered me whilst I worked in his laboratory. M. Nicolle and he very kindly placed at my disposal their unique collection of colours, which had been supplied them by various firms (notably the Farbenfabriken of Elberfeld). By their suggestions, without which this work would not have been accomplished, they saved me much time and labour. MM. Nicolle and Mesnil had been studying the influence of a large number of colours on various trypanosomes, chiefly Trypanosoma Brucei and to a less extent T. Evansi, T. equinum, and T. Gambiense. Their work was undertaken after the publication of Ehrlich and Shiga's paper on the action of Trypanroth, one of the benzidine colours, on Trypanosoma equinum. M. Mesnil suggested that I should investigate the action of these colours on T. dimorphon which differs in many ways from the above trypanosomes.

The great importance of an exact knowledge of the etiology of malaria has given a remarkable impetus to the study of mosquitoes. It has resulted in the growth, during the last few years, of a very extensive literature relating to these insects, and especially to those of the genus Anopheles, which serve as the alternative and definitive hosts of human malarial parasites. Comparatively few writings, however, deal with their internal anatomy.