To what extent do the parasites predispose to pneumonia? Compare for this purpose the two columns of Table 8 showing active and inactive pulmonary parasitism. In Rodentia and Galli alone do we note that active parasitism is effective, there being no passive cases. In all the other orders, animal invaders of the lung are more often encountered as quiescent or encapsulated bodies, therefore as findings incidental to the autopsy and perhaps not concerned in the cause of death. In Ungulata the inactive parasitisms are five times as frequent as the active inflammatory lesions. It might be added that the list is made up of cases wherein we saw parasites whether determined or not, an explanation of the apparently small number of cases; there were many more in which such invaders were suspected but not found and therefore excluded. BRONCHIECTASIS. Bronchiectasis affecting the smallest tubes, or bronchiolectasis, is not at all uncommon in verminous pneumonitis and is explained as due to the degeneration of the wall, the surrounding progressive ulceration, to accumulation of inspired air and its retention by the obstruction. There is described a generalized bronchiolectasis, chiefly in young human beings, due to a destructive bronchiolitis; this has not been seen. Non-verminous bronchiectasis of the middle sized bronchi such as is seen in human chronic bronchitis, simple or tuberculous, is quite uncommon. Widening of the bronchial lumen may be divided, as I see its pathogenesis, into (a) that due to congenital weakness of the walls, (b) that due to obstruction permitting air to pass into but not out of a bronchus because of a ball-valve obstruction or weakness of expiratory power, (c) that due to external pressure by tumors or distortion by fibrous tissue either within the lung or pleura and (d) that due to inflammatory weakening of walls, augmented by loss of supporting pulmonary tension, accummulation of secretion and the dilating effect of inspiration preparatory to and incidental to coughing. How important the last three auxiliary factors may be in the cases explicable under a, b, c, can easily be speculated upon and may vary in different cases.