The precise effect to be attributed to each cause is difficult to estimate. Often, of course, two or more factors will be present, concurrently and interdependently. In an enquiry made in 1910 by Dr. Chate, into the condition of 570 children (307 boys and 263 girls) in a rural or semi-rural district of Middlesex who were suffering from malnutrition, it was found that poverty was the principal cause in 29.5 per cent. of the cases among the boys, and 26.1 per cent. among the girls. Adenoids, worms, rickets, carious teeth and oral sepsis accounted for 32.7 per cent. among the boys, and 33.3 per cent. among the girls. Improper diet was the main cause in 2.3 per cent. of the cases. In 69 cases malnutrition was due to some disease such as tuberculosis, chronic bronchitis, etc., while in 13 cases it was attributed to overcrowding, and in 10 cases to overwork with insufficient sleep.[467] In the following year a similar enquiry was made by Dr. Tate in a suburban residential area of the same county. Out of 167 cases, defective nutrition was found to be due to poverty and neglect in 23.3 per cent.; to rickets, adenoids, worms or digestive disorder in 28.5 per cent.; to lung affection in 5.4 per cent.; in 7.2 per cent. malnutrition "appeared to be associated with some previous or present condition of ill-health, to account for which no organic mischief could be found at the time of inspection"; while in 33 instances no obvious cause could be assigned.[468] Footnote 467: Report of the Chief Medical Officer of the Board of Education for 1910, pp. 29-30. Footnote 468: _Ibid._, for 1911, p. 30. At Bootle the School Medical Officer reports that out of 289 cases of sub-normal nutrition, the cause is to be sought in 78 per cent. in some definite disease or physical defect (including disturbances of digestion due to improper feeding); in 17 per cent. there are no definite signs of organic disease; while in 5 per cent. malnutrition is due to neglect.[469] Footnote 469: Report of the School Medical Officer for Bootle for 1912, p. 17.