has been made during the four weeks’ period of the acute epidemic and where the descriptions have been recorded by painstaking observers, the similarity with our present findings is very striking. I would refer in particular to one report made in 1893 in Petrograd by Kuskow. His report deals with 40 carefully studied cases in which records both macroscopic and microscopic were accurately made. One of the great difficulties in placing an accurate interpretation upon the pulmonary findings lies in the fact that true pneumonia as seen in epidemic influenza in man has not been reproduced in animals. Furthermore, as the majority of the fatal human cases of epidemic influenza with their associated pneumonias present a mixed infection of the lung tissues, it is difficult, if not impossible, to indicate the lesions which have resulted through the activity of one of these as against those induced by the other bacteria present. In our own carefully studied cases wherein bacteriological cultures were taken from every lung there was not a single instance in which the influenza bacillus was present in pure culture. This is more fully commented upon in the studies by Dr. Holman, but the point we wish to make here is the difficulty in arriving at a conclusion in our material as to the actual effects induced by any one type of organism. As it is fully discussed by Dr. Holman we are convinced of the importance of the influenza bacillus in this epidemic. We also appreciate that pneumonia lesions in animals have been induced by a variety of materials gained from influenza patients, but yet in view of the abnormal manner of producing such lesions these are hardly comparable to those in man. We may well expect severe œdema, inflammation and hemorrhage, if in guinea pigs, rabbits and monkeys we introduce by intra-tracheal insufflation large quantities of fluid suspensions of bacteria. And thus we find positive results obtained by the use of a filtrable virus, streptococci, influenza bacilli and other organisms. The lung is a sensitive tissue which quite readily responds to a variety of irritants. In many respects some of these lesions simulate those in influenza, but still we are far from the conclusion that the disease, influenza, with all its manifestations has been actually reproduced.