The question at once comes to mind whether this gray stage is but the late event of what we have previously spoken of as influenza-pneumonia or whether this condition is superadded to what may begin as an influenza-pneumonia but end in a pulmonary inflammation with a mixed infection. Dr. Holman was not able to demonstrate a sufficient difference in the bacteriology of the lobes in the gray stages from those in the early acute stage to be able to say that the flora changes at a certain time during the progress of the disease in the individuals. It is possible, and there is some evidence in support of this, that the earlier stages of the pneumonic process represent the reaction to the influenza bacillus and that during this period the response is fairly uniform and similar owing to the fact that this infection has but a short incubation period and a high pathogenicity. In such an event the particular micro-organism may bring about a peculiar response of its own before the other organisms with which it is associated have the opportunity of producing damage. Subsequently, however, these secondary organisms impose their peculiar reactions upon an altered lung, thus inducing an inflammatory lesion which differs from the preceding reaction and also differs from the reaction usually induced by those organisms upon relatively healthy tissues. It is difficult to account for the very irregular distribution of the gray lesions by an explanation concerning the influenza bacillus alone, or by the characters peculiar to the secondary infection. There is an entire want of character to these gray lesions which makes them differ from other types of pneumonia known to us. It is well to lay particular stress upon this peculiarity in the distribution and extent of the lesions within the lobes; and it is also important to appreciate the difference in the appearance of these gray areas from those of true lobar or broncho-pneumonia. Finally there is another point in which this stage of the pneumonic process differs from that of pneumococcus lobar pneumonia. In frank lobar pneumonia the reactions taking place in the involved portion of the lung are fairly uniform in all its parts. The stage of red hepatization occupies about that amount of lung which subsequently shows itself in the state of gray hepatization. In other words, all of those areas which appear gray are preceded by this peculiar red consolidation, and all of the area occupied by the red hepatization will pass through the phases of gray hepatization before entering upon the final stage of resolution.