Of papers recently published which concern the properties of immune-sera and bear upon the general theory of immunity one of the most important is that of Bordet2 on antisensibilisatrices (anti-immunebodies, anti-amboceptors). This observer obtained an anti-immune-body by injecting the serum of a normal animal (rabbit) into an animal of another species (guinea-pig), and found that there was developed an anti-immune-body which had the property of neutralising the various immune-bodies which might be developed by active immunisation of the first animal. In this way a certain community as regards combining properties was demonstrated among the immune-bodies of a given species of animal. He studied the properties of the anti-immune-body, and in particular showed that it did not combine with the cytophile group of the immune-body, and therefore did not prevent the usual combination of the cell-receptor with the immune-body. This fact he held to be inconsistent with Ehrlich's views regarding the amboceptor constitution of immune-body. His observations on the neutralising effect of the anti-immune-body were carried out by means of haemolytic sera. Ehrlich and Sachs3 confirmed the chief results obtained by Bordet, but so far from admitting the establishment of any objection to the amboceptor theory, claimed that they supplied strong evidence in support of it. They maintained in fact that the anti-immune-body acted by combining with the com piementophile group of the amboceptor, and thus prevented the union of complement, stating also that the results showed that the various immune-bodies from the same species had a similar complementophile apparatus. The theoretical bearings of the facts established will, however, be discussed later.

In the course of our experiments on haemolytic sera we have met with the following phenomenon which appears of some interest. It consists in the agglutination of the corpuscles of an animal by its own complement through the medium of the corresponding immune-body derived from another animal, and was observed first in the case of ox's corpuscles, the immune-body used being obtained from the rabbit. The fundamental fact is that if a certain amount of immune-body and ox's complement be added to ox's corpuscles, scarcely any lysis of the corpuscles occurs but they become agglutinated into large masses which cannot be dissociated by shaking. The immune-serum from the rabbit contains some agglutinin, but the degree of agglutination produced by this is quite trifling compared with that seen when complement also is added. There is thus no doubt that the agglutination phenomenon depends on the cooperation of two substances in a manner comparable to what obtains in lysis. The following are the chief facts regarding the conditions of occurrence of the agglutination and the nature of the agglutinating substance in the ox's serum.

The Bacillus cloacae liquefies gelatin very slowly, sometimes taking a month or more to do so. It is in consequence occasionally a source of delay and of great inconvenience to the bacteriologist. In this paper it has been shown that by using appropriate methods the time necessary for demonstrating the liquefaction of gelatin by this organism may be shortened to a week.

1. Three fully-established, and two probable, cases of infection with B. paratyphosus B producing a typhoid-like illness have been found in a series of 176 cases of typhoid.

2. Preliminary culture in a fluid medium containing dulcite is of great assistance in isolating paratyphoid organisms from mixtures such as faeces.

3. The diagnosis of paratyphoid fever can generally be made from the agglutinative reactions of the serum.

4. Absorption tests are necessary for the positive or negative diagnosis of mixed infections.

5. The structure of the agglutinated masses of paratyphoid and Gaertner bacilli varies with homologous and heterologus sera, and is of diagnostic import.

6. Gaertner and paratyphoid agglutinins are more thermostabile than typhoid agglutinin by 5°–10° C.

7. The agglutinations of paratyphoid, hog-cholera and Gaertner bacilli with a series of typhiod sera are described, and the circumstances which influence the presence and amount of these secondary agglutinins discussed.

In a recent publication1 I described a gas analysis apparatus suitable for rapid and accurate laboratory work. This apparatus is, however, somewhat cumbrous, and cannot easily be conveyed from place to place, as is very often required in investigations relating to questions of hygiene. It also occupies a good deal of working space in a laboratory, as it cannot be moved from its place without a good deal of trouble. On the other hand the already existing forms of portable gas analysis apparatus for technical work are too inaccurate for many of the requirements of work in hygiene and physiology. I have therefore designed an apparatus with a view to meeting these defects as far as possible2.

Since it would hardly be possible to conceive a more complex medium for the conveyance of disease than cows' milk, the solution of the problems connected with the origin and source of epidemic diarrhoea is not materially advanced by the general recognition of the fact that in the majority of fatal cases, cows' milk is the vehicle of infection.

In 1898 I published1 a brief account of certain amœbulæ and flagellulæ found by me during the previous year in mosquitoes near and in Ootacamund, India. Similar parasites were frequently observed by me subsequently in various species of Culicina, especially in C. fatigans Wiedemann, and once in an Anophelina. Since then what appear to be the same, or at least closely allied, organisms have been described as occurring in Anophelina by Chatterjee, Stephens and Christophers, and L´ger, the last of whom named them Chrithidia fasciculata. Their habitat appears to be principally the intestinal cavity of the larva, pupa and imago. Many of them (as still well shown in an unstained preparation of my own made in Calcutta in 1899) have a considerable resemblance to trypanosomes—a resemblance which appears to be further suggested by the stained preparations of Léger, Christophers, and Stephens.