2. _Nausea and vomiting._--This symptom is quite constant, especially early in the disease; and projectile vomiting is quite characteristic of intracranial pressure or irritation. 3. _General septic appearance._--This of course will vary in the different conditions under consideration, but in all is it quite manifest. 4. _The vision_ is very frequently affected due to the choked disk that is present. 5. _Temperature, pulse, and respiration_ are very frequently disturbed. 6. _Definite focal symptoms_ of brain localization are of the utmost importance in the diagnosis. 7. _Blood and spinal fluid examinations_ give very valuable information. 8. _Röntgenographic findings_ are at times valuable. 9. _Exploratory operation and treatment_, as in lues, is at times necessary to make a diagnosis. MENINGITIS (a) _Serous meningitis._--One of the first signs is the increasing headache, at first localized, usually near the seat of the perforation or path of infection, and soon becoming diffuse over the head. The patient loses his appetite, his tongue becomes coated, the emunctaries become sluggish in their action, and nausea is a very common symptom. The temperature rises, and, if the septic form is going to follow, this rise is often quite rapid, so that there may occur small chills from the infection of the cerebrospinal fluid. The pulse and respiration rate is now considerably increased. The patient is very irritable and restless, and does not sleep. As soon as the fluid increases within the cavity there is observed the characteristic syndrome of rolling the eyes, especially upward, the neck is drawn backwards, and finally the leg upon the thigh and thigh upon the abdomen. Attempts to straighten them out is resisted and appears to be painful,--Kernig’s sign. Stroking the bottom of the feet with some semisharp instrument or the finger-nail will cause the big toe to turn up instead of down,--Babinski’s sign. Taking the head and tilting it forward against the chest will cause the limbs to be drawn up,--Brudzinski’s sign. All the other symptoms, as pressing over the peroneal nerve and muscle (Gordon’s sign), which will cause the extension of the toes, the stroking of the anterior tibial surface (Oppenheim’s sign), or the stroking of the region of the external malleolus (Chaddock’s sign), will produce retraction of the toes. All these signs, I say, prove that the upper neuron (within the cranium) is involved. The patient now will lapse into unconsciousness, and be roused with more or less difficulty to again relapse in the same condition. The pupils become sluggish in their action, at first becoming small, then irregular, and finally dilated.