During the period when work on the p resen t pro ject was proceeding, quite a number of consultations were held with D r. Joseph Hawkins of the M erck Therapeutic Institute, who had developed a method of testing vestibular function in cats, in conjunction with his work on the effects of streptom ycin on this function. We had independently both a rrived at testing both ro tational and optokinetic nystagmus and in many r e ­ spects the principles of testing were alm ost identical. In con trast with our cinem atographic method of recording, however, D r. Hawkins had developed an electronic method of recording nystagmus by placing one electrode over the tem ple and the other electrode between the eyebrows. Simultaneous runs, using both methods of recording, showed a very high degree of correlation . Dr. Hawkins’ apparatus possesses the advantages that recordings can be read instantly, and also that nystagm us can be tested with the eyes closedo With our machine it is not possible to te s t nystagmus without fixating. Disadvantages of Hawkins’ machine are that a 2-man team is required to adm inister the te s ts and that the m achinery is influenced by any vagaries in the flow of e lec trica l power.