In cases of frontal abscess, the _mental condition_ of the patient demands special consideration. Some definite degree of moral perversion will usually be noticed, the patient--presuming that he is in a conscious condition--making himself as objectionable as possible. He will upset his food, disarrange his bedclothes, disobey orders, and even pass his urine and fæces in his bed though well aware of his wrong-doing. When questioned he answers with suspicion, when examined he demands to know the why and the wherefore of the various details of the investigation. An ophthalmoscopic examination is especially difficult to carry out in a satisfactory manner. In a case recently under my care--one in which a frontal abscess was drained three times before a cure was obtained--these curious mental perversions were observed each time, and the patient subsequently acknowledged that he had performed the various acts wittingly, but was unable to deny himself the opportunity of irritating those around him. It has been stated that these mental changes are only to be observed when the abscess involves the _left_ frontal lobe. In my own experience no such lateral differentiation has been noticed. _Anosmia_ may be present if the patient is in a condition to respond to the tests requisite to prove the defect. In most cases, however, considerable difficulty will be experienced in applying the tests, and the results obtained are too variable. Anosmia will be associated with impaired power of taste. _Pupillary changes._ ‘If the abscess is of large size, the pupil on the same side is in a state of stabile mydriasis; if small, it may be sluggish and contracted.’[56] =The TERMINAL stage.= In _fatal_ cases death results from the pressure exercised by the expanding abscess on the bulbar centres, or from the bursting of the abscess into the ventricular or meningeal spaces. During this terminal stage the pulse becomes very rapid, the respiration irregular and Cheyne-Stokes in character, whilst the temperature rises rapidly, reaching 105-110 degrees F. Invasion of the lateral ventricle is evidenced by violent convulsions, rigidity of the extremities, opisthotonos, retraction of the head, trepidation, and prostration. The pupils become widely dilated, and remain in that condition till death ensues. =Treatment.= In the operative treatment of _otitic temporo-sphenoidal and cerebellar abscess_ two courses are available:--(1) to trephine directly over the abscess through the squamous or cerebellar regions, postponing mastoid exploration till a later date (the two-stage operation); and (2) to carry out the complete mastoid operation, searching for the ‘stalk’ of the abscess, and draining the abscess into the now-united middle ear and antrum (the one-stage operation).