1. Park, E. A., and Howland, J.: The dangers to life of severe involvement of the thorax in rickets, Johns Hopkins Hosp. Bull., 1921, xxxii, 101. Holt, E. L.: Diseases of Infancy and childhood, New York, 1916.

2. Findlay, L.: Historical survey of rickets: Special Report Series, No.

20, National Health Insurance, London, 1918. Ferguson, M.: A study of the social and economic factors in the causation of rickets, Special Report Series, No. 20, National Health Insurance, London, 1918.

3. Schmorl, G.: Die pathologische Anatomie der rachitischen Knochenerkrankung, Ergebnisse d. inn. Med. u. Kinderheilk., 1909, iv, 403.

4. Dick, J. L.: The teeth in rickets; Proc. Royal Soc. of Medicine, Section for the study of the diseases of children, 1915 -16, ix, 83

5. Hess, A. F., and Unger, L. J.: Prophylactic therapy for rickets in a negro community, Jour. Amer. Med. Assn., 1917, lxix, 1583. Hess, and Unger: An interpretation of the seasonal variation of rickets, Amer. Jour. Dis. Child., 1921, xxii, 186. Hess, and Unger: The diet of the negro mother in New York City, Jour. Amer. Med. Assn., 1918, lxx, 900.

6. Thompson, J.: Clinical study and treatment of sick children, Edinburgh, 1921.

7. Soranus: Diseases of Women. Cited by Findlay, (2).

8. Glisson, F.: Treatise on rickets, London, 1651.

9. Mellanby, E.: Accessory food factors (vitamines) in the feeding of infants, Lancet, 1920, 1, 1290. Mellanby: An experimental investigation on rickets, Lancet, 1919, Mar. 15, 407. Medical Research Committee: Report on the present state of knowledge concerning accessory food factors (vitamines), Special Rep. Series, No. 38, National Health Insurance, London, 1919. Mellanby, E.: The part played by the fat-soluble A in the etiology of rachitis, Jour. of Physiol., Proceedings Soc. Physiol., 1919, lii, liii. Mellanby, M.: Experimental evidence demonstrating the influence of a special dietetic factor on the development of the teeth and jaws, The Dental Record, Feb., 1920.

10. Schabad, J. A.: Zwei Falle von sogenannten "Spatrichitis". Der Mineralgehalt der Knochen und der Mineralstoffwechsel in Vergleich zu der Kindlichen Rachitis, Mittheil. a.d. Grenzgebiet d. Med. und Chirurg., 1911, xxiii, 82.

11. Hess, and Unger: The clinical role of fat-soluble vitamine: Its relation to rickets, Jour. Amer. Med. Assoc, 1920, lxxiv, 217.

12. Mori, M.: Ueber der sogennanten Hikan. (Xerosis conjunctivae infantum ev. Keratomalacie), Jahrbuch f. Kinderheilkunde, 1904, lix, 175.

13. Bloch, C. E.: Eye diseases and other disturbances in infants from deficiency in fat in the food, Ugeskrift f. Laeger, 1917, lxxix, 349. Cited by Jour. Amer. Med. Assoc, 1917, lxviii, 1516. Bloch: Clinical investigations of xerophthalmia and dystrophy in infants and young children, Jour. of Hyg., 1921, xix, 283.

14. Wells, H. G.: Cited by Blunt, K, and Wang, C. C: The present status of vitamines, Jour. Home Econ., 1921, xiii, 98.

15. McCollum, E. V.: The supplementary dietary relationships among our natural foodstuffs, Harvey Lecture Series, 1916-17. Also Jour. Amer. Med. Assn., 1917, lxviii, 1379.

16. Hopkins, F. G.: Position of vitamines in clinical medicine, Brit. Med.

Jour., 1920, July 31.

17. Hess, and Unger: An interpretation of the seasonal variation of rickets, Amer. Jour. Dis. of Child., 1921, xxii, 186.

18. Findlay, L.: The etiology of rickets: A clinical and experimental study, Brit. Med. Jour., 1908, ii, 13. July 4. Findlay: Diet as a factor in the cause of rickets, Archiv. of Pediatrics, 1921, xxxviii, 151.

19. Paton, D. N., Findlay, L., and Watson, A.: Observations on the cause of rickets, Brit. Med. Jour., 1918, ii, 625, Dec. 7. Paton, D. N., and Watson, A.: Etiology of rickets, Brit. Med. Jour., 1921, i, 594.

20. McCollum E. V., Simmonds, N., Parsons, H. T., Shipley, P. G., and Park, E. A.: Studies on experimental rickets. 1. The production of rachitis and similar diseases in the rat by deficient diets, Jour. Biol. Chem., 1921, xlv, 333.

Shipley, Park, McCollum, Simmonds, and Parsons: Studies in experimental rickets, ii. The effects of cod liver oil administered to rats with experimental rickets, Ibid., 343.

Shipley, Park, McCollum, and Simmonds: Studies on experimental rickets. iii. A pathological condition bearing fundamental resemblances to rickets of the human being resulting from diets low in phosphorus and fat-soluble A: The phosphate ion in its prevention, The Johns Hopkins Hosp. Bull., 1921, xxxii, 160.

McCollum, Simmonds, Shipley, and Park: Studies on experimental rickets. iv. Cod liver oil as contrasted with butter fat in the protection against the effects of insufficient calcium in the diet, Proc. of the Soc. for Exper. Biol. and Med., 1921, xviii, 275.

Shipley, Park, McCollum, and Simmonds: Studies on experimental rickets. v. The production of rickets by means of a diet faulty in only two respects, Proc. of the Soc. for Exper. Biol. and Med., 1921, xviii, 277.

McCollum, Simmonds, Shipley, and Park: Studies on experimental rickets. vi. The effects on growing rats of diets deficient in calcium, Amer. Jour. Hyg., 1921, I, 492.

Shipley, Park, McCollum, and Simmonds: Studies on experimental rickets. vii. The relative effectiveness of cod liver oil as contrasted with butter fat for protecting the body against insufficient calcium in the presence of a normal phosphorus supply, Amer. Jour. of Hyg., 1921, 1, 512. McCollum, Simmonds, Shipley, and Park: Studies on experimental rickets. viii. The production of rickets by diets low in phosphorus and fat-soluble A, Jour. Biol. Chem., 1921, xlvii, 507.

21. Sherman, H. C, and Pappenheimer, A. M.: A dietetic production of rickets in rats and its prevention by an inorganic salt, Proc. Soc. for Exper. Biol. and Med., 1921, xviii, 193. Hess, A. F., McCann, G. F., and Pappenheimer, A. M.: Experimental rickets in rats. ii. The failure of rats to develop rickets on a diet low in vitamine A, Jour. Biol. Chem., 1921, xlvii, 395.

22. Howland, J., and Kramer, B.: Calcium and phosphorus in the serum in relation to rickets, Amer. Jour. Dis. of Child., 1921, xxii, 105.

23. Hansemann, D.: Ueber den Einfluss der Domestication auf die Enstehung der Krankheiten, Berliner klin. Wochenschr. 1906, xliii, 629, and 670. Smith, E.: Archeological Survey of Nubia, ii, 21, Cairo. Cited by Findlay (2).

24. Stefansson, V.: Personal communication.

25. Hooton, E. A.: On certain Eskamoid characters in Icelandic skulls, Amer. Jour. of Physical Anthropology, 1918, 1, 53.

26. Butler, H. B.: Importance of Oral Hygiene during childhood, Amer.

Jour. of Pub. Health, 1921, xi.

27. Mackenzie, W. L.: The Carnegie United Kingdom Trust. Physical welfare of mothers and children (of Scotland), East Port, Dunfermline. 1917.

28. Mellanby, E.: Accessory food factors (vitamines) in the feeding of infants, Lancet, 1920, i, 1290.

29. Hess, A. F., and Unger, L.: The clinical role of fat soluble vitamin:

Its relation to rickets, Jour. Amer. Med. Assoc, 1920, lxxiv, 217. Huldschinsky, K.: Treatment of tetany with ultraviolet rays, Ztsch. f. Kinderh., 1920, xxvi, 207, Sept. 13. Huldschinsky: Die Behandlung der Rachitis durch ultra-violett bestrahlung, Ztschr. f. orthop. Chir., 1920, lxxxix, 426. Hess, and Unger: An interpretation of the seasonal variation of rickets, Amer. Jour. of Dis. of Child., 1921, xxii, 186.

30. Shipley, Park, McCollum, and Simmonds: Unpublished data.

31. Buchholz, E.: Ueber Lichtbehandlung der Rachitis und andere Kinderkrankheiten, Verhandlungen der Gesellschaft fur Kinder-heilkunde in der Abteilung fur Kinderheilkunde der 76 Versammlung der Gesellschaft Deutscher Naturforscher und Aerzte in Breslau, 1904, xxi, 216.

32. Palm, T. A.: The Geographical Distribution and Etiology of Rickets, The Practitioner, 1890, xlv, 270, and 321.

33. Raczynski, J.: Communications sur le rachitisme. 1. Recherches experimentales sur le manque d'action du soleil domme cause du rachitisme, Compt. rend. de L'Assocation Internationale de Pediatre, Paris, 1913, 308.

34. Fraenkel, E., and Lorey, A.: Archiv und Atlas der normalen und pathologischen Anatomie in typischen Rontgenbild, Hamburg, Lucas Grafe and Sillem, 1910.

35. Phemister, D. B.: The effect of phosphorus on growing normal and diseased bones, Jour. Amer. Med. Assoc, 1918, lxx, 1737.

36. Huldschinsky, K.: Heilung von Rachitis durch Kunstliche Hohensonne.

Deutsch. med. Wochenschrift, 1919, xlv, 712.

37. Winkler, F.: Ueber die Strahlungstherapie der Rachitis, Monatschr. f.

Kinderheilk., 1919, xv, 520. Putzig, H.: Die Behandlung der Rachitis mit Kunstlicher Hohensonne, Therap. Halbmonatschr., 1920, viii, 234.

38. Karger, P.: Zur Kenntniss der zerebralen Rachitis, Monatschr. f.

Kinderheilk, 1920, xviii, 21.

39. Riedel, G.: Die Erfolge der Quartzlichtbestrahlung bei Rachitis.

Munchen. med. Wochenschr., 1920, lxvii, 838.

40. Sachs, F.: Untersuchungen uber den Einfluss des Ultraviolettlichtes auf die latente Sauglingstetanie, Jahrb. f. Kinderheilk., 1921, xciii, 167. Munchen. med. Wochenschrift, 1921, lxviii, 985.

41. Erlacher, P.: Ueber Heilerfolge bei Rachitis nach Quattzlichtbestrahlung, Wiener klin. Wochenschr., 1921, xxxiv, 241.

42. Mengert, E.: Ueber verbeugende Hohensonnenbestrahlung gegen Rachitis, Deutsch. med. Wochenschrift, 1921, xlvii, 675.

43. Hess, A. F.: The clinical role of the fat-soluble vitamin. Its relation to rickets, Jour. Amer. Med. Assn., 1920, lxxiv, 217.

44. Hess, A. F., and Unger, L. J.: The cure of infantile rickets by sunlight, Jour. Amer. Med. Assn., 1921, lxxvii, 39.

45. McCollum, E. V., Simmonds, N., Shipley, P. G., and Park, E. A.:

Studies on Experimental Rickets. viii. The production of rickets by diets low in phosphorus and fat-soluble A, Jour. Biol. Chem., 1921, xlvii, 507.

Shipley, McCollum, and Simmonds: Studies on experimental rickets. ix. Lesions in the bones of rats suffering from uncomplicated beriberi, Jour. Biol. Chem., 1921, xlix, 399.

McCollum, Simmonds, Shipley, and Park: Studies on experimental rickets. xii. Is there a substance other than fat soluble A associated with certain fats which plays an important role in bone development?, Jour. Biol. Chem., 1922, xlix, 5.

McCollum, Simmonds, Shipley, and Park: Studies on experimental rickets. xv. The effect of starvation on the healing of rickets, Johns Hopkins Hosp. Bull. 1922, xxxiii, 31.

Powers, G. F., Park, E. A., Shipley, P. G., McCollum, E. V., and Simmonds, N.: Studies on experimental rickets, xiv. The prevention of the development of rickets in rats by sunlight, Jour. Amer. Med. Assn., 1922, lxxviii, 159.