110. Opie, Freeman, Blake, Small, and Rivers: Pneumonia following Influenza;—J. A. M. A., 1919, 72, 556.

111. Orteconi, Barbie, et LeClerc: Contribution à l’Etude de la Flore Microbienne de la Grippe;—Presse Med., 1918, 26, 508.

112. Orth: Thrombosen bei der Spanischen Krankheit;—Deut. med. Wchnschr., 1918, 44, 1298.

113. Park, Wm. H.: Bacteriology and Possibility of Influenzal Vaccine as a Prophylactic;—N. Y. Med. J., 1918, 108, 621.

114. Park, Wm. H., and Williams, A. W., et al: Studies on the Etiology of the Pandemic of 1918;—Am. J. Pub. Health, 1919, 9, 45.

115. Parker, J.: A Filterable Poison Produced by B. influenzæ;—J. A. M. A., 1919, 72, 476.

116. Peacock: Influenza;—Boston Med. & Surg. J., 1919, 180, 185.

117. Peacock, T. B: Review of the Influenza or Epidemic Catarrhal Fever of 1847–1848;—The British and Foreign Medico Chirurgical Review, 1849, 7, 90.

118. Pfeiffer, R.: Vorlaufige Mittheilungen über die Erreger der Influenza;—Deut. med. Wchnschr., 1892, 18, 28.

119. Pfeiffer, R.: Die Aetiologie der Influenza;—Zeit. f. Hyg., 1893, 13, 357.