The lesion within the lymph nodes following the early serous inflammation was of a non-suppurative kind. The lymph follicles lost their outline, and the lymphocytes were diffused through the stroma so that no recognition of the germinal centers could be found. The dilated sinuses within the lymph nodes were filled with large mononuclear cells, of the type of endothelial cells, along with some lymphocytes and leucocytes. Subsequently the leucocytes increased very materially so that the lymphatic fluid became purulent. Smears obtained from larger lymphatics showed leucocytes and varieties of bacteria. This was particularly true in those cases where the pulmonary lesion had itself become purulent either localized in a patchy pneumonia or with lobar involvement. Under these circumstances focal areas of purulent infiltration were found within the tissues of the gland occupying the regions of the former follicles and leading to necrosis or abscess. Where such purulent reaction and abscess formation were found within the lymph nodes there was remarkably little reaction in the tissues of the immediate vicinity. No attempt at the development of a pyogenic membrane or granulation tissue was observed, though this probably does take place in the cases recovering. In only one instance did we observe the development of the peculiar fibrosis along the lymphatic channels where the freshly cut section of lung reveals prominent and raised demarcation between the lobules. This response has been described by MacCallum as unique for the streptococcus inflammation of the lung. The character of the exudate within the lymphatics with many mononuclear cells and blood is not to be considered singular for the influenza pneumonia. It has been found that in ordinary lobar pneumonia, as well as in the pneumonia following measles, the early pulmonary reaction is accompanied by the dilatation of the lymphatic channels along the bronchi, containing serous fluid, mononuclear cells, blood and leucocytes, while occasionally thrombosis entangling bacteria is also encountered. It would seem, however, that the lymphatics in epidemic influenza can more readily recover their normal character when a streptococcus infection is wanting.