The trend of fertility in Wales and the Southern and Midland counties of England was demonstrated and discussed in the previous sections of this enquiry.1 The corresponding vital statistics for Northern England are given in the present concluding section and, in addition, the results that have been found are briefly reviewed for the country as a whole. For the Northern counties the same methods have been employed as in the two previous sections. Briefly, the actual birth-rate has been measured by the number of births per 1000 married women aged 15–45, while as a rough assessment of how far a changing age distribution of married women has affected its level, a potential birth-rate and fertility ratio have also been calculated. The potential birth-rate gives the number of births per 1000 married women aged 15–45 obtained by applying Tait's fertility ratios 48.75, 41.25, 30 and 15 to the number of married women in the age groups 15–19, 20–24, 25–35 and 35–45 respectively. The fertility ratio is the ratio of the actual to the potential birth-rate.

There is much evidence to indicate that viruses, in certain cases at least, have an antigenic structure of comparable complexity to that of the bacteria. Hughes (1933) found that the serum of animals immunized with the yellow-fever virus contained two independent antibodies—precipitins and protective antibodies; the precipitinogen was distinct from the virus. Craigie & Wishart (1936) in investigations of the vaccinia virus have shown that, in addition to the elementary bodies, virus suspensions contain two soluble precipitable substances, the “L” antigen which is labile at 56° C. and the “S” antigen which is stable at 95° C. These antigens were readily demonstrated by precipitation, agglutination and complement fixation. Their nature and origin have not, however, been precisely determined. Bedson (1936), working with the psittacosis virus, prepared a soluble antigen, which was independent of the elementary bodies. It was most satisfactorily demonstrated by complement fixation.

The diameter of the virus of rabbit fibroma has been estimated by filtration through graded membranes to be about the same as that of vaccinia (125–175 mµ) and by centrifugation to be 126–141 mµ.

That of the rabbit papilloma virus appeared by filtration to be 23–35 mµ and by centrifugation 32–50 mµ.

1. Streptococcus pyogenes multiplies readily in sterilized milk stored at 22 and 18° C., and more slowly at 15° C. In fresh raw milk this organism begins to multiply slowly only after 48–72 hours of storage at 18–22° C. In laboratory pasteurized milk the result is similar, but both commercially pasteurized milk and raw graded milk bottled for distribution sour too rapidly for multiplication to take place after artificial contamination. These facts suggest that widespread epidemics are rarely due to extensive multiplication of S. pyogenes in milk during commercial or household storage.

2. The initial degree of contamination of milk with S. pyogenes has no influence upon this organism's ability to multiply during storage.

3. The failure of S. pyogenes to multiply during storage is due to (a) its natural reluctance to grow at atmospheric temperatures, (b) the bacteriostatic action of the milk, and (c) the readiness with which saprophytic bacteria multiply at atmospheric temperatures.

4. It is contended that infected cows play a major part in the spread of milk-borne S. pyogenes epidemics, and relevant literature is quoted to support this view. It is urged that routine investigation of apparent milk-borne epidemics should include the immediate bacteriological examination of an individual sample of milk from every cow concerned in the supply under suspicion.

1. Horgan's (1936) findings with regard to heat sterilization of B. typhosus vaccine are not confirmed.

2. Silver in the form of katadyne or electro-katadyne appears to be an effective sterilizing agent for B. typhosus suspensions.

3. Katadyne and electro-katadyne have no destructive action on Vi, O or H agglutinogens of B. typhosus.

4. Electro-katadyne, even when used in excessive doses, has no detrimental effect on the immunizing activities of Vi antigen.

5. Electro-katadyne sterilized suspensions of V strains of B. typhosus are more effective immunogenic agents than those sterilized by heat and phenol.

6. The bactericidal properties of electro-katadyne, though impaired in 0·85 per cent saline, are adequate as a means for preserving vaccine.

7. It is suggested that katadyne sterilized suspensions of V strains might be of value in testing for the presence of Vi agglutinins in human sera since they are hypersensitive to Vi antibody while retaining most of their resistance to O antibody.

8. In view of the suggestion by Felix that additional antigens with activities similar to those of Vi antigen may exist in bacteria other than B. typhosus, it may be found that the electro-katadyne process has an application in the preparation of vaccines generally, particularly those which have hitherto proved ineffectual in prophylaxis.

1. A simply made selective tellurite medium for the isolation of Corynebacterium diphtheriae and the identification of its types has been described.

2. The ingredients of this medium are easily obtained and can be stored for any length of time making the medium readily available at short notice.

3. Large or small quantities of the medium can be made with equal facility.

4. When grown on the medium, C. diphtheriae will produce colonies characteristic of its type, be it gravis, mitis or intermediate.

5. The appearance of the colonies has been described and has been shown to resemble closely, in the case of each type respectively, the appearances described by the Leeds workers (Anderson et al. (1931)) on their medium in the original papers.

6. The possibilities of the use of this medium for diagnostic routine swab examinations have been briefly referred to.

A new type of pathogenic Salmonella for the fowl has been described. Its somatic “O” antigen corresponds with factors VI, VII of potsdam. It occurs only in the specific phase, but its flagellar “H” antigen contains at least two distinct and separate antigenic complexes, which commonly occur in organisms that are not even remotely related. The one complex (the first, en-, antigen, α phase of Kauffmann and Mitsui) contains factors enx, which represent also the factors of the specific phase of abortus-equi. The other complex (the second, d-, antigen, β phase of Kauffmann and Mitsui) contains factor d, which comprises the type phase of stanley, muenchen and typhi.

Single cells containing factors enx on multiplying constantly yield variants containing factor d as well as offspring that retain antigenic complex enx. In the same way single cells containing apparently only specific factor d will bring forth new cells, most of which retain the parental antigenic structure, but a small proportion of the progeny will acquire specific factors enx instead of d.

When a broth culture of amersfoort in either the enx or d phase in an apparently pure form, as judged by the agglutination test, using heterologous sera which contain agglutinins either against factors enx (or en) or d, is used for the preparation of sera, agglutinins of approximately the same titre for both variants are produced in the sera.

As a result of the information given above the following antigenic structure is proposed for Salmonella amersfoort:

Somatic “O” antigen—VI, VII.

Flagellar “H” antigen—

(1) α phase of Kauffmann and Mitsui—enx.

(2) β phase of Kauffmann and Mitsui—d.

1. The day-to-day records over a period of 4–6 months of 167 normal women's physical changes and subjective phenomena have been collected by a new method. These women submitted data from 780 complete menstrual cycles. In addition, a smaller group submitted data which have been used for physical changes only. One woman's individual record of certain phenomena was obtained over a period of 8 years.

2. The average length of the menstrual cycle was 27·8 days with a standard deviation of 3·4 days. Some individual's cycles were characteristically short or long, regular or irregular. No woman menstruated with complete regularity (measured in days) over a period of 6 months. Twenty-three per cent of the menstrual periods began between 7.30 and 9.30 a.m., and the average duration of the flow was about 4·5 days.

3. Records from one case of intermenstrual, probably ovulatory, bleeding were obtained over a period of 6 months (Chart 2).

4. The periodicity of each subjective phenomenon as shown by the combined results has been recorded graphically, and these figures themselves constitute a summary of the results. Thus for fatigue, abdominal pain, backache, headache, breast changes, sexual feeling and intercourse, depression, elation, tendency to cry, irritability, intellectual capacity and tension see Figs. 5–19. Individual data of interest have been discussed in the light of the combined results.