THE VERTIGO of endolymphatic hydrops is of three types: the premonitory, the critical, and the residual. In a given case premonitory vertigo may or may not occur. When it does it is a valuable harbinger of more severe trouble to come. Regarded and diagnosed at this time as a labyrinthine symptom with a potentially grave future this premonitory imbalance is a most valuable therapy indicator. It is associated usually with a sense of aural pressure and a "seashell" tinnitus likened often, to a soft "roaring" or "buzzing" with a variable admixture of low and high frequencies. The vertigo is mild and usually amounts to "unsteadiness" as the vestibular labyrinth is called upon by active movement. There are rarely vegetative system reactions. Cochlear function may be found wanting in acute discrimination of words though pure tones are within the normal range or modesty impaired in the low frequencies. Anticholinergic drugs, blocking