for important secondary lesions and morbid processes. Their significance in relation to the central nervous system from these points of view calls for special notice. Aneurysm is of course an arterial disease which has long been known; and although as a rule it belongs to the domain of the surgeon, it must be remembered that when an aneurysm occurs in one of the internal cavities of the body, it comes within the scope of the physician. The recognition of the more minute aneurysms which give rise not infrequently to cerebral hæmorrhage, as well as those within phthisical cavities, which by their rupture cause serious or fatal hæmoptysis, is of comparatively recent date. Amongst the causes which modern investigations have shown to affect the arteries may be specially mentioned certain acute febrile diseases, the effects of which may become revealed later on; and syphilis, both acquired and congenital, the injurious results of which upon the vessels are but too well-known. In this connection may also be noted the advance in knowledge with regard to the mutual secondary effects of diseases of the heart and vessels upon each other.
3. The so-called "functional disorders" of the circulatory system, sensory and motor, constitute another most important group of affections, which no doubt are now much more frequent than formerly, or at any rate have assumed a conspicuous prominence at the present day, mainly as the outcome of the altered
