As innervation and circulation go hand in hand or closely follow each other, my own view is that both vaso-motor and molecular changes, temporary in character, probably occur in the central nervous system in grave hysterical cases. Whatever the temporary conditions are, it is evident, on the one hand, that they are not states of simple anæmia or congestion, and, on the other hand, that they are not inflammations or atrophies. Patients with hysterical manifestations of the gravest kind as a rule are free for a time from their harassing and distressing symptoms. This could not be if these symptoms were due to lesions of an organic nature. Sudden recoveries also could not be accounted for if the changes were organic. {213} Lloyd[28] contends that most hysterical symptoms, if not all, are due to abnormal states of consciousness. The development of this idea constitutes his argument for the recognition of the disease as a true psychosis. In the reflex action, not only of the lower spinal cord and ganglia of special sensation, but of the highest centres of the brain, he sees the explanation of many of the characteristics of hysteria. In other words, he finds that the sphere of the disease is more especially in the automatic action of the brain and cord. [Footnote 28: _Op. cit._] Dercum and Parker[29] have published the results of a series of experiments on the artificial induction of convulsive seizures which bear upon this discussion of the pathology of hysteria. The experiments were performed by subjecting one or a group of muscles to a constant and precise effort, the attention being at the same time concentrated on some train of thought. The position most frequently adopted was the following: The subject being seated, the tips of the fingers of one or both hands were placed upon the surface of the table, so as to give merely a faint sense of contact—_i.e._ the fingers were not allowed to rest upon the table, but were held by a constant muscular effort barely in contact with it. [Footnote 29: _Journal of Nervous and Mental Disease_, vol. xi., October, 1884, pp. 579-588.] Tremors commenced in the hands; these became magnified into rapid, irregular movements which passed from one limb or part to another until the subject was thrown into strong general convulsions. Opisthotonos, emprosthotonos, and the most bizarre contortions were produced in various degrees. No disturbances of sensation were at any time present. Disturbances of respiration and phonation were often present in a severe seizure, and the circulatory apparatus was profoundly affected. A flow of tears, and occasionally profuse perspiration, were sometimes induced. After severe seizures large quantities of pale urine were passed. The reflexes were distinctly exaggerated. No unconsciousness was ever observed, but a progressive abeyance or paresis of the will. Nitrite of amyl seemed to arrest the convulsive seizures at once.