When the thrombus extends _inwards_ along the meningeal veins, meningitis, meningo-cerebritis, and cerebral abscess result. 2. _Symptoms resulting from toxic absorption or dependent on the transmission of infected material to other parts of the body._ _Optic neuritis_ is present, according to Hunter Tod, in about 50 per cent. cases. It develops rapidly and attains a high degree of intensity. _Headache_ is usually intense in character, persistent, but little remedied by drugs and presenting marked exacerbations. It is often most acute over the affected region. The _mental condition_ of the patient is subject to variation. In the average case mental symptoms are quite disproportionate to the severity of the disease. Sometimes the patient is cheerful, perhaps rather excited, retaining his faculties to the last, in other cases--as the result of excessive toxic poisoning--he lies in a stuporose, typhoid-like state. When the thrombus is associated with meningitis, meningeal symptoms predominate. _Vomiting_ is often a conspicuous feature, generally of the so-called ‘cerebral’ type, a regurgitation without nausea and retching. The _pulse_ is rapid, the rhythm irregular, and the tension lowered. The _temperature_. The formation of the thrombus is usually notified by the advent of one or more severe rigors, the temperature rising to 103° or more. During the height of the illness the temperature is high but remittent, and rigors are frequent. The occurrence of a series of rigors is almost certainly indicative of sinus thrombosis. Any marked remission of temperature is succeeded by profuse sweating, but, with this exception, the skin remains dry and burning. Each rigor implies the extension of the thrombus to other venous channels or the transference of infected particles, by means of the blood-stream, to other parts of the body. In the young general convulsions are often observed. The tongue is brown and dry, the breath foul and diarrhœa of common occurrence. The skin may be jaundiced, and septic rashes are prone to develop. The liver and spleen may be enlarged and tender. Cough and foul sputum point to pulmonary infarction.