The results are collected in Table I, and it may be concluded that:
1. Under ordinary conditions in the south of England B. tuberculosis may remain alive and virulent in cow's faeces exposed on pasture land for at least 5 months during winter, for 2 months during spring and for 4 months during autumn. In summer no living organisms were demonstrated after 2 months.
2. Under special conditions, e.g. protection from direct sunlight, the survival period may be 4 months during summer. In autumn faeces protected from earthworms, etc., yielded bacilli after 6 months.