Derrick and Thatcher1 have recently shown that the admissions for asthma in Brisbane in the 5–10 year age-group falls rapidly from 30 per 10,000 of population to a minimum of 6 per 10,000 of population at the age of twenty-seven. The initial incidence does not return to its former level until past the age of sixty, and it continues to rise. This work was reported at the August meeting of the Australian and New Zealand Association for the Advancement of Science in Sydney last year, and it appeared likely to me2 that this could be an effect of testosterone depressing the sensitivity to H substances released in asthma. Especially did this seem likely owing to the unchanging incidence in the female. Dungan3 pointed out that admissions of asthma cases to hospital did not reflect asthma incidence, but rather the supervention of status asthmaticus, and this is undoubtedly true.