[41]. Jour. Am. Med. Assn., 1918, lxxi, 2068.

[42]. Wolbach: Bull. Johns Hopkins Hosp., 1919, xxx, 104.

[43]. Spooner, Scott and Heath: Jour. Am. Med. Assn., 1919, lxxii, 155.

[44]. Kinsella: Jour. Am. Med. Assn., 1919, lxxii, 717.

[45]. MacCallum: Jour. Am. Med. Assn., 1919, lxxii, 720.

[46]. Pritchett and Stillman: Jour. Exper. Med., 1919, xxix, 259.

[47]. Hirsch and McKinney: Jour. Am. Med. Assn., 1918, lxxi, 1735.

[48]. Parker: Jour. Am. Med. Assn., 1919, lxxii, 476.

[49]. Opie, Freeman, Blake, Small and Rivers: Jour. Am. Med. Assn., 1919, lxxii, 556.

[50]. See discussion on pages [115] to [118].