_Senile tuberculosis_, contrary to what has sometimes been stated, is fairly common though it is often latent; a patient with pulmonary tuberculosis may have little or no cough, expectoration, fever, or night sweats, and the physical signs, if present, may be regarded as those of bronchitis and emphysema or bronchiectasis, unless the sputum is available and examined for bacilli. Such unrecognized cases are an obvious danger in institutions, and it may be added that hereditary disposition plays a much less important part in the aged than in early life. Senile tuberculosis, however, is usually either a persistence of that infection or a recrudescence of quiescent infection, and is seldom primary. The disease may be chronic or acute, and either local or generalized. The _senile heart_ has attracted much attention, and myocardial degeneration and fibrosis due to past infections or to coronary arteriosclerosis are extremely common. The myocardial change is of great importance in reducing the reserve power of the heart, so that cardiac failure is prone to supervene in acute infections, such as influenzal pneumonia. Chronic valvulitis akin to and associated with arteriosclerosis is common; the mitral valve is often affected and incompetent, with a loud systolic murmur at the apex which is displaced outwards; but the most characteristic lesion of advanced years is pure aortic stenosis; this is commonly regarded as part of the arteriosclerotic process in the aorta, but, as I have often noticed, the aorta may be remarkably healthy and even thinner than usual in old people with extensive calcification of the valves reducing the aortic orifice to a chink; it has indeed been thought that such stenosis of the aortic valves may protect the aorta from strain and so from arteriosclerosis. Although involvement of the bundle of His giving rise to the symptom complex of Stokes-Adams disease, and angina pectoris may complicate aortic stenosis, the presence of this valvular defect is compatible with remarkable prolongation of life. This may be due to the more placid life of these old patients, as is suggested by Sir Clifford Allbutt,[215] who regards aortic stenosis as more unfavourable in persons under 55 years of age than in their elders. _Aneurysm of the large arteries_ is rare in the aged, although arteriosclerosis is common. Diffuse dilatation especially of the arch of the aorta and of the common iliacs is not infrequent, and occasionally latent saccular aneurysms are present. In rare instances large abdominal aneurysms causing pain or remaining latent until rupture occurs are reported. Among 112 abdominal aneurysms collected by Nunneley[216] 15 were over 50 years of age; these figures included 32 from St. George’s Hospital, three of them being over 65 years of age. Miliary aneurysms are of course extremely common in the subjects of cerebral haemorrhage.