IN response to the kind invitation of the Section, I propose to develop certain neN ideas with regard to the curious syndrome of synchronous and rhythmic palatopharyngo-laryngo-oculo-diaphragmatic myoclonus. The name more frequently employed for this syndrome in neurological literature is " nystagmus of the soft palate ", which is not, in my opinion, a good term, presupposing as it does an analogy with the common ocular nystagmus, which is an entirely different phenomenon. Herbert R. Spencer, who, in a remarkable observation published in 1886, created the term " pharyngeal and laryngeal nystagmus " has himself stated, in a second communication, that this term is not altogether accurate, and has employed instead the word " clonus ". It gives me great pleasure, at the beginning of this lecture, to pay homage to the British physician, Herbert R. Spencer, who, at a time when it was unknown, drew the attention of neurologists to this subject.This syndrome seems to me to merit attention for a variety of reasons. Firstly, from the clinical point of view, because it is a rare syndrome. of which not more than about a hundred cases have been published; secondly, from the physiological point of view, because its study throws new light on certain automatic functions and on certain co-ordinating centres of the brain-stem ; and, lastly, from the point of view of anatomy and pathological anatomy, for post-mortem examinations have revealed localized lesions of certain regions of the nervous system and, in particular, of the inferior olives. The pathology of the olives, which is not well known, and which has never been extensively studied, is, in my opinion, one of the most absorbing problems in neurology. It is a problem in which I have taken a special interest during the last few years, along with Pierre Mollaret and Ivan Bertrand, my assistants at the Neurological Clinic of the Salpetriiere.Historical. The historical aspect of the subject is not without interest. The first cases were published by ear, nose, and throat specialists-for example, the case of Politzer (1862), of Schwartz (1865), and of Boeck (1866). A case specially deserving attention is that published by Kupper (1873). The patient, a butcher zf Elberfeld, presented a myoclonic syndrome, of which Kupper has given us a very accurate description. The myoclonic movements were rhythmic, occurred at a rate of 140