_Senile paraplegia_ may be divided into four etiological groups: (1) The functional dysbasias or pseudo-paraplegias described by Marie and Léri,[211] which in general terms resemble those met with during adult life, but the varieties are less distinct in the old. Quesnel[212] recognizes three groups of functional disturbance of walking in old people: (_a_) the slight and usually curable, (_b_) severe functional disturbance depending essentially on the mental state of the patient, and (_c_) the organo-functional in which a bony, articular, or nervous lesion is present; thus confinement to bed for a fracture may cause a functional paraplegia. (2) Spastic paraplegia due to sclerosis in the lateral and posterior columns of the spinal cord; the influence of arteriosclerosis, as advocated by Oppenheim, has been the subject of some debate, and Lejonne and Lhermitte point out that the nervous lesions are not necessarily perivascular and that there is a want of proportion between the vascular and the nervous changes. (3) Paraplegia of cerebral origin with descending degeneration in the cord and mental deterioration. (4) Paraplegia from muscular fibrosis and contracture, the central nervous system being intact. From the presence of emphysema bronchitis is prone to occur in the old. _Lobar pneumonia and bronchopneumonia._ Lobar pneumonia has always been considered the great enemy of the aged; it is often latent, and may be found after sudden death and in persons supposed to have died of old age, because they were walking about or complained not at all or only of trivial symptoms. In spite of Charcot’s[213] considered opinion to the contrary, it is probable that pneumonia has been often used to describe what was really bronchopneumonia. For Roussy and Leroux[214] found that among 300 necropsies at the Hospice Paul Brousse there were 164 cases, or 55 per cent, of bronchopneumonia and only 4 cases, or 1·4 per cent, of lobar pneumonia. The bronchopneumonic areas are triangular with the base towards the pleural surface, and indeed are infarcts, due to pre-existing endarteritis obliterans which disposes to secondary infection. In 110 out of the 164 cases of bronchopneumonia there was arterial thrombosis, which was of older date than the infected areas of infarction and bronchopneumonia.