The preparation of a medium that would allow the bacillus of diphtheria to grow and exclude all other organisms would be an ideal medium for those whose work is concerned with that organism, but, as such a medium has not yet been devised, we must be content with the modifications of the ordinary media which we possess. Various varieties of media have been prepared for the purpose of favouring the growth of B. diphtheriae, but very little seems to have been done with regard to selective media.

Certain difficulties attendant upon bacteriological diagnosis recur constantly in connection with the notification, isolation, and discharge of patients suffering from diphtheria, and from every point of view it becomes increasingly necessary to seek means to minimise, as far as possible, the number of ‘missed’ and ‘carrier’ cases.

1. When fleas bit through films of Tuberculin, Vaccine Lymph, and Staphylococcus Emulsion lying upon the human skin, no inoculation was observed in 188 instances out of 195. In six of the experiments with Tuberculin, inoculation followed, which possibly was not due to the flea-bites. Controls gave positive results.

2. When the same materials were rubbed over recent flea-bites, no inoculations followed. Controls were positive.

3. A very minute dose of Tuberculin, such as might be conveyed by a flea's proboscis, will produce a recognisable reaction in a susceptible person.

4. The bearing of the results on the question of plague transmission is discussed.

This Congress was originally announced to take place in 1910 (see Journal of Hygiene, 1909, vol. IX. pp. 347—356) but the date was subsequently altered to 1912. Certain changes in the organization have been made, as appears from a notice which has recently reached us. This notice states that: