hours and conditions of labour and to the speed of work as shown by the output curves. Laboratory tests for the detection of accumulated fatigue have not sufficiently justified the trouble they involve, but observations as to complex reaction time with letter or colour tests, determination of acuity of auditory and visual sensations, and records of the systolic blood-pressure may be found to serve as an index to the incidence of fatigue when other methods are not applicable. There is no need to amplify these points. It only remains to suggest that inquiry on such lines be applied to groups of adolescent workers to discover the extent to which industrial fatigue may be under-mining the health and physique of growing girls. It was stated above that the absence of accurate data in the shape of records of the health of industrially employed girls made it impossible to arrive at any exact estimate of the effects of such work, but the sickness returns of industrial Insurance Societies must have been accumulating a vast mass of evidence as to the particular ailments and diseases to which employed girls are especially liable, so that an examination of these records may be extremely enlightening. The secretary of the Insurance Section of the Northern Counties Weavers' Amalgamation informed us that at the present time the sickness returns of this Association are not tabulated according to ages, but that such tables could be obtained from the local Unions and a complete estimate made if the need be proved. One Weavers' Society, the Nelson and District Weavers' Insurance Society, No. 1882, which is outside the Amalgamation, does indeed tabulate its records according to ages, but the total number of women and girls in this society reaches only 5982, so that far-reaching conclusions cannot be drawn from its experience. Unfortunately not all the members of the Trade Union are in the Insurance section of their Society for the National Insurance Benefit, but many belong to such Approved Societies as the Prudential, the Blackburn Unity, etc., so that evidence from these sources cannot be regarded as entirely conclusive. Nevertheless, were such data available for purposes of comparison between one industry and another, considerable evidence as to the particular effects of different industries might be obtained.