Interpretation of this case is manifestly difficult. Four possibilities exist: Syphilis, manic depressive psychosis, traumatic brain disease, and functional shock effects. More than two years had passed between the trauma and the change of character. Skull trauma in a syphilitic. =Case 17.= (BABONNEIX and DAVID, June, 1917.) A soldier, 31, sustained fracture of the occiput from shell-burst, and thereafter showed confusion and total loss of memory. Operation November 11 withdrew bony fragments and clots, whereupon the man returned practically to normal. He developed, however, a few seizures, in which he struggled, fell, and lost consciousness, afterward suffering from headache. The tendon reflexes were increased. The occipital cicatrix was a little depressed and slightly painful on pressure. Lumbar puncture showed a very slight lymphocytosis (5 to 6 cells), practically negative globulin reaction, and a low albumin titer. There were no signs of syphilis in the eyes. The W. R. in the serum was strongly positive. Very possibly the traumatic phenomena in this case can be safely disengaged from the syphilitic phenomena. _Re_ the mechanism by which trauma evokes or accelerates the course of neurosyphilis, it is probable that most neuropathologists believe that the _commotio cerebri_ causes sundry chemical or physical effects in the nerve tissues such that spirochetes are moved into new and more dangerous places, or such that more appropriate food is supplied to the organisms, which then begin to multiply. Whether the organisms live in a kind of symbiosis in the tissues under ordinary circumstances in the pre-paretic period of the development of neurosyphilis, is unknown. Possibly fat embolism should be added to the list of possible causes of the hastening of the neurosyphilitic process. Fat embolism in the brain has been shown by various authors to be accompanied by minute hemorrhages, in the midst of which by proper stains the fat embolism can be made out. Shell-wound in battle: General paresis. =Case 18.= (BOUCHEROT, 1915.)