1. In the course of the examination of sputum from cases of lobar pneumonia, observations have been made on the incidence of the chief types of pneumococci. In the district from which the material was obtained, there was an apparent local diminution in the number of cases of lobar pneumonia due to Type II the figures were 326 per cent. of Type II cases in the period 1920–22, and only 74 per cent. in the period 1924–27. The incidence of Type I was approximately the same in the two periods, the percentages being 3O6 and 343.

2. Several different serological varieties of pneumococci have been obtained from the sputum of each of several cases of pneumonia examined at various stages of the disease. This has occurred most frequently in cases of pneumonia due to Type I, and in two instances four different types of Group IV were found in addition to the chief types. The recovery of different types is facilitated by the inoculation of the sputum (preserved in the refrigerator), together with protective sera corresponding to the various types in the order of their appearance.

3. Two interesting strains of Group IV pneumococci have been obtained from pneumonic sputnm.

One was an R strain which produced typical rough colonies, yet preserved its virnlence for mice and its capacity to form soluble substance. This R pneumococcus developed a large capsnle in the mice, which died of a chronic type of septicaemia. A strain producing smooth colonies was obtained from it in the course of a prolonged series of passage experiments.

The second strain, which was proved not to be a mixture, agglutinated specifically with the sera of two different types. In the peritoneal cavity of the mouse the specific soluble substance of each type was produced.

4. A method of producing the S to R change through ageing of colonies on chocolate blood medium containing horse serum is described. After two to three days' incubation small rough patches appear in the margins of the smooth colonies, and from these pure R strains can be isolated.

5. It has been shown that the R change is not equally advanced in the descendants of virulent pneumococci which have been exposed to the action of homologous immune serum. Some R strains form traces of soluble substance in the peritoneal cavity of the mouse; these revert readily to the virulent S form and, in addition, are able to produce active immunity. Others show no evidence of S antigen; spontaneous reveraion takes place with difficulty, if at all, and they are incapable of producing active immunity. The stronger the immune serum used, the more permanent and complete is the change to the R form.

6. Restoration of virulence to an attenuated R strain, with recovery of the S form of colony and of the original serological type characters may be obtained by passage through mice. The change from the R to the S form is favoured by the inoculation of the R culture in large doses into the subcutaneous tissues; but the most certain method of procuring reversion is by the inoculation of the R culture, subcutaneously into a mouse, together with a large dose of virulent culture of the same type killed by heat. Incubation of such a mixture in vitro does not induce reversion.

7. Reversion of an R strain to its S form may occasionally be brought about by the simultaneous inoculation of virulent culture of another type, especially when this has been heated for only a short period to 60° 0., e.g. R Type II to its S form when inoculated with heated Type I culture.

8. Type I antigen appears to be more sensitive to exposure to heat than Type II antigen, since the former loses the power to cause reversion when heated to 80° C., whereas Type II culture remains effective even after steaming at 100°C.

9. The antigens of certain Group IV strains appear to be closely related to that of Type II, and are equally resistant to heat. Steamed cultures of these Group IV strains cause the R form derived from Type II to revert to its S form, while they fail to produce reversion of the R form derived from Type I.

10. The inoculation into the subcutaneous tissues of mice of an attenuated R strain derived from one type, together with a large dose of virulent culture of another type killed by heating to 60° C., has resulted in the formation of a virulent S pneumococcus of the same type as that of the heated culture.

Thp newly formed S strain may remain localised at the seat of inoculation, or it may disseminate and cause fatal septicaemia.

The S form of Type I has been produced from the R form of Type II, and the R form of Type I has been transformed into the S form of Type II.

The clear mucinous colonies of Type III have been derived both from the R form of Type I and from the R form of Type II, though they appear to be produced more readily from the latter. The newly formed strains of Type III have been of relatively low virulence, and have frequently remained localised at the subcutaneous seat of inoculation.

Virulent strains of Types I and TI have been obtained from an R strain of Group IV.

11. Heated R cultures injected in large doses, together with small doses of living R culture have never caused transformation of type, and only rarely produced a reversion of the R form of Type II to its virulent S form.

12. The results of the experiments on enhancement of virulence and on transformation of type are discussed and their significance in regard to questions of epidemiology is indicated.

The Bacillus capsulatus-mucosus group may be said to have originated with the discovery of the pneumobacillus by Friedländer in 1883. This organism was isloated from the lung in a case of croupous pneumonia, and it is interesting to note, as can be ascertained from a study of the literature, that the discovery appears to have been of an accidental nature, and, as was pointed out by Weicheselbaum, that Friedläder had really confused it with the pneumococcus. Subsequently, numerous other bacilli, which showed such marked similarity to the pneumobacillus in morphological, cultural and biological characteristics as to render differentiation among them a matter of extreme difficulty, were isolated by various workers from widely different sources. In a paper published in 1896 Fricke furnishes a list of the representatives of this group of organisms which had up to that time been found. Many of these were subsequently used as type strains by later workers and some are still available and frequently employed.

1. A minority only of scarlatina streptococci are agglutinated by antisera for individual strains and no group agglutination has been observed.

2. Absorption tests reveal the existence of common or generalised agglutinogenic constituents but these are not restricted to scarlatina strains and can be recognised among the majority of the haemolytic streptococci isolated from various sources.

3. Though certain serological groups among scarlatina streptococci may be recognised as corresponding generally to “types” described by Smith and Griffith, there is such considerable antigenic overlap among the different groups that the differentiation and relationship of strains cannot be expressed satisfactorily by formulating definite serological types.

4. A system of serological analysis of scarlatina and other haemolytic streptococci is suggested (see Table IV).

5. While strains presenting particular serological characters may be associated more frequently with scarlatina, haemolytic streptococci with common serological characters occur both in scarlatina and other conditions. No essential serological distinction can be drawn between scarlatinal and other haemolytic streptococci and a “Streptococcus scarlatinae” group cannot be defined by serological methods.

6. Among the haemolytic streptococci derived from conditions other than scarlatina no relationship exists between serological characteristics and toxigenic properties (as evidenced by cutaneous reactions to culture nitrates).

We have to thank Drs J. Smith and F. Griffith for cultures of the type strains referred to in the text.

Malaya, or at least the part of it with which I am well acquainted— the coast districts of Selangor— was free from measles until 1910. In that year infection was probably imported from India by immigrnat coolies, and the disease spread rapidly through the rubber estates on which there was a considerable non-immune population of locally born Indians.

A study was made of the available statistical data bearing on the epidemiology of typhoid in Palestine. It apears from this analysis that:

1. The typhiod epidemicity is not due to a single source such as contaminated water or food. The seasonal prevalence of the disease corresponds with the normal seasonal incidence of typhiod, and is, therefore, in the nature of a contact infection.

2. There is no striking difference in age, sex or race susceptibility. In Tel Aviv the age group 5–14 shows a lower incidence than the corresponding age group in Jerusalem or the higher age group 15–29 in Jerusalem and Tel Aviv. There is, however, no difference in susceptibility between the age group 15–29 in Jerusalem and that in Tel Aviv.

3. From a graphic comparisos, the calculation of the coefficient of correlation of the limited experience (six years), and a comparison of the prevalence of the disease in the immigrant and indigenous population, there appears to be a significant correlation between the net population increment and epidemicity. These results, if confirmed by a longer experience, are in accord with those obtained in the remarkable mice experiments conducted by the English and American investigators.

4. Although, at the beginning, the morbidity and mortality is higher in the immigrant group, there is an evident tendency at equalisation, and in the second year the incidence in the indigenous population is the same as that among the immigrants.

5. The above results indicate the path of control: (a) every immigrant, particularly those between the ages 5–29, should be properly vaccinated against typhoid. By raising the resistance of the new population, the possibility of epidemics among them, and consequently later among the resident population, will be averted; (b) the reduction of endemic typhoid can be brought about by reducing the dosage of the infectious microbes. This can only be brought about by concentration of effort on the early detection and isolation of cases and the vaccination of all contacts. These two measures would seem to offer a prompt and relatively simple solution to the typhoid problem in Palestine.

I. Life-Cycle. Colony Formation, Sporing, Papilla Formation.

If any bacterium is sown in the usual way from a fluid suspension on to a plate of suitable culture medium, colonies arise from the multiplication of single bacteria. These colonies grow at their margins ar a rate roughly constant for the species. When the colony has reached a certain size, which is again roughly constant for the species, it ceases to grow or continues growing very slowly. Thus for example colonies of streptococci grow to 1 mm. in diameter, those of coliforms to 3 or 6 mm. The colonies do not continue to grow until they have covered the whole plate. This limitation of growth is not due to the using up of the food supply or to the drying of the medium, since, if a second sowing of the same bacterium is made between the arrested colonies, a new crop of colonies arises.

1 Twort (1907) obtained lactose fermenting variants of B. typhosus after prolonged growth in this sugar. These variations do not however occur frequently and regularly. They are probably examples of mutation from a homozygous strain (Mode A above).

2 The variations mentioned take place in culture where their origin from papillae can be seen. It is likely that exaltation of virulence is an adaptive variation of the same kind occurring in a host.

(1) Fifty S. aureus and 30 S. albus strains obtained from infective processes in man have been investigated. Such cultural reactions as were completed did not differentiate between strains of S. albus and S. aureus, or serve to group these cocci; we found, however, that 94 per cent, of the S. aureus strains fermented mannite, as opposed to 40 per cent, of the S. albus strains. These results are in accordance with the findings of Cummins and Cumming (1913) and Hine (1922).

(2) A close degree of correlation between pathogenicity for rabbits, pigment formation, and biochemical activity was noticed among the S. aureus strains. Out of 19 pathogenic strains of S. aureus, 9 showed medium pigmentation and 10 were strongly pigmented.

(3) Anti-sera were prepared by inoculating rabbits with living cultures, 24 hours old, of the various strains. The S. aureus rabbits and a few of the S. albus received two preliminary doses of the specific vaccine, but little or no protective action was afforded from the doses of living cocci injected.

(4) Nineteen out of 25 cultures of S. aureus killed rabbits, but only 3 out of 18 cultures of S. albus.

(5) Fifteen strains of S. aureus and 15 of S. albus were used for the preparation of anti-sera, and tested against as many antigens as possible, by the methods described by Dudgeon and Bamforth.

(6) Cultures of S. aureus produced efficient anti-sera more readily than S. albus cultures, but when an active S. albus anti-serum was produced, it appeared to be as effective as the S. aureus anti-sera.

(7) A marked difference in efficiency between S. aureus and S. albus antigens was noted. S. aureus antigens were almost three times more active than S. albus antigens.

(8) Pathogenic strains of S. aureus and S. albus produced more efficient precipitin antigens than non-pathogenic.

(9) From the microscopical examination of the deposit formed in the precipitin reactions, a difference was noted between S. aureus and S. albus antigens.

(10) The study of the precipitin reactions has failed to show any hard and fast dividing line between staphylococci of different colours, or of different cultural reactions. We are inclined to agree with Winslow, Rothberg and Parsons (1920) and with Dudgeon's original view in 1908, that the pyogenic, Gram-positive staphylococci must be regarded as members of one common family.

1. The tuberculin reaction properly applied is a reliable test of the presence of tuberculosis in cattle.

2. A method of segregation is described by which any herd can be rendered tuberculin negative in three to four years without diminution of the herd.

3. Evidence is given that recovery from a tuberculous infection can take place in cattle.

4. Calves can only be infected with tuberculosis after birth, such an infection may, however, take place extremely rapidly within the first few days of life.

5. Artificial feeding of calves with sterilised milk must be supplemented by some vitamine-containing food, otherwise “joint ill,” corresponding to rickets in human beings, will develop at about the third or fourth month. Bull calves are more susceptible to “joint ill” than heifers.

Summarising the results obtained in this series of experiments, it would appear that, in the case of Bact. aertrycke infection spreading among a closed community of mice:

(1) The character and severity of the epidemic are mainly determined by the virulence of the infecting bacterial strain.

(2) Strains of high virulence may give rise to non-fatal persistent infections, maintaining their full virulence over long periods of time within the spleens of the infected mice.

(3) Strains of low virulence may persist for long periods of time within such closed populations, spreading to some extent among the mice at risk, causing occasional deaths, and leading to an appreciable number of latent infections.

(4) It would appear that virulence and power to spread are highly corre lated.

In both of these diseases, locomotor ataxia and general paralysis of the insane, the necessary antecedent is now generally recognised as syphilitic infection. Whether these two types of nervous degeneration occur at random in those so predisposed to their development, or whether some underlying factors at present unknown or only suspected operate selectively is a problem of some importance.

1. Cultures were obtained from 69 cases of ringworm of children in London County Council Schools.

2. Three of them were cases of favus, the parasite in each case being Achoroion Schōnleinii.

3. Microsporums are responsible for most of the ringworm, and were isolated from 54 of the 69 cases, or 78 per cent. Microsporum audouini was found in 70 per cent, of the Microsporum infections; M. lanosum and M. felineum each in one case; and 4 other cultures were obtained, comprising 3 species which have not yet been identified.

4.Endothrix Trichophytons were found in 17 per cent, of the cases and include the species Trichophyton crateriforme, T. sulfureum, T. acuminatum and T. violaceum.

5.A list of the species isolated arranged, according to the new classification of Ota and Langeron, is given.

6.The results are compared with those previously obtained in London by Fox and Blaxall, and Adamson, with which they broadly agree.

A pre-scorbutic condition has been described, but not, as far as the writer is aware, a pre-Beriberi condition, to the existence of which it is the purpose of this communication to draw attention.

Pneumococci form a group of organisms of which the individual strains exhibit wide differences in character. Like the streptococci, certain types of which they closely resemble, they show a variability in their predilections and behaviour bewildering to those who are attempting to classify them. Not only are pneumococci known to cause a great variety of lesions about the body, but they have also been found in the throats of a large proportion of healthy persons who apparently suffer no inconvenience from their presence—Stillman (1916, 1917), Glynn (1923) and others.

Experiments begun in 1925 in Egypt led the writer quickly to realise that comparable results in nutrition studies upon pigeons could only be obtained by a careful choice of the breed. It was found that lightly coloured birds and especially white bids were extremely sensitive to climatic change or to the harmful effects on an inadequate diet.

(1) Samples of faeces of 391 cows in apparently good health have been examined and it has been demonstrated that 6 (1.53 per cent.) of the cows were excreting tubercle bacilli.

(2) When the faeces of almost all the cows on founrteen farms were examined it was found that five cows on four farms were excreting tubercle bacilli.

Our thanks are due to the Medical Research Council for the grant which enabled us to carry out this investigation.

The subjection of the scrotum of the dog for 10 minutes daily for 28 days to a stream of water at 39·5 40·0° C. does not materially affect the testes. It is unlikely that ordinary hot bathing affects male fecundity.

In the year 1577 King Philip II of Spain issued a decree to all Spanish officials in the New World ordering them to obtain and send him answers to a questionnaire consisting of fifty searching inquiries, intended to elicit information which would “facilitate the good government and ennoblement” of “the Indies.”

The possibility that the prevalence of diseases in which there is no specific causal organism may be affected by the prevalence of other diseasses of a contagious nature is well recognised. Even in the early days of bactriology interrelationships between infectious diseases and puerperal septicaemia were suspected on purely statistical grounds. Longstaff (1891), for example, pointed out the remarkably close correlation between the seasonal variations and the secular trends of the mortalities of erysipelas and childbed fever—a relationship so close that he “found it difficult to avoid the conclusion that they were both due to the one poison.” A somewhat similar but less striking association was shown with other inflammatory diseases, such as pyaemia, scarlet fever, “rheumatism of the heart or pericardium” and diphtheria. Even more emphatic were the views of Minor (quoted by Longstaff) who, with reference to the association between erysipelas and puerperal fever, gave reasons for the belief that there existed an intimate connection between them, and that “in any place where erysipelas is found, there will be found puerperal fever.”

Although many measures which may influence the mortality of infants have within recent years come into operation, it is convenient and permissible to classify these into one or other of two broad categories. In the first place, many general measures intended to ameliorate the life and health of the people at all ages must be taken into consideration. Here we have such improvements as have been effected or attempted in the unhealthy conditions of urban life, in particular, improved housing, improved domestic and municipal sanitation, control of the milk supply, etc. The manner in which these may affect the health of infancy is obvious and need not be enlarged upon. In the second instance, we have to consider the effects of those measures which have been specially directed to the infant and the pregnant or nursing mother. From a small beginning in private philanthropic work has now sprung a vast national machinery of maternity and child welfare, a scheme which resolves itself into component parts directed towards improvements in the conditions affecting the three special periods of infant life, the ante-natal, natal and postnatal.

The experiments herein described show that:

(1) Of the 268 coliform organisms isolated from 32 samples of certified milk, 65.7 per cent, fall within the true B. coli group and 18–6 per cent, in groups X and Y of Stewart.

(2) 54–1 per cent. of the organisms, i.e. those of the B.faecalis alkaligenes group and those in subgroups 1, 2 and 3 of MacConkey which fermented lactose, gave a negative V. and P. and a positive M.R. reaction, can be assumed to be of faecal origin.

(3) 45–9 per cent., namely those organisms of the B. proteus group, those of subgroup 4 of the B. coli group and those of groups X and Y are of the type generally found in soil and water.

(4) All of the 32 samples examined contained coliform organisms in a dilution of 1 in 10 as shown by bile salt agar plates. None of these samples, however, gave a positive reaction with the presumptive test in two out of three tubes of 1/10 c.c. dilution. The presumptive test cannot, therefore, be relied upon to give a true indication of the presence of coliform organisms in milk. The inaccuracy of the test may be due in part to the structure of the ordinary Durham's tube which fails to ensure the collection of the gas produced.

(5) Although the majority of the coliform organisms present in milk ferment lactose other members of the group which are not lactose fermenters occur and consequently their presence is not demonstrated by the presumptivetest.