I am sorry to say that I have not kept any comparative statistics of my examinations; at the same time they have all left an impression upon my mind, which is this: that I feel more confidence in the results obtained from the use of the Maddox test in the routine tests that I always make of refractive cases. If this test shows any marked degree of heterophoria it has been my habit to retest the patient by the Stevens method, which is usually the same, provided the patient has a sufficient amount of intelligence to give correct answers to the questions put to him. During this test the patient is allowed to sit for some time in front of the prisms, and the eye muscles allowed to relax from that first impulse at muscular effort that follows the placing of the prisms in front of the eyes. To my mind both tests are good and fairly accurate in the hands of one who is thoroughly familiar with their use and shortcomings, provided your patient is able to answer correctly. Many times, on re-examining a patient, I have discovered what appeared to be a great change in the muscular conditions, but after repeated examinations I have usually found it was the patient, and not the muscles, that was erratic. When Dr. Hubbell speaks of ¼° of difference between the Maddox and Stevens tests, he has more confidence than I have in the average judgment of patients that come under our care. SAYER HASBROUCK. DEAR DOCTOR: Your note asking my opinion of the comparative usefulness of the Maddox rod and the phorometer is at hand. In the detection of heterophoria I regard the rod as the most convenient and trustworthy instrument used. The distance at which the test is made and the dissimilarity of the images seen usually eliminate all actual effort to hold the eyes in any particular position other than that in which they stand the most easily. Accordingly the deviation is quickly noted and readily measured. So satisfactory has this modest little instrument been in my examinations that I now rarely resort to other methods. The amount of deviation sometimes shown between this and other instruments is so slight as to make little or no difference in the measures employed for correction. It is to be noted that cases not unfrequently occur in which a hyper-sensitive, or, on the contrary, an enervated condition exists, which is not fully indicated by any instrument. An educated judgment will here have to supply conclusions not to be drawn by any hard-and-fast rules.