It would seem that by this time all the problems concerned with the fundamental anatomy of the temporal bone should have been worked out and comprehended. Yet during last year, Claus1 published a detailed study of the anatomy based on an examination of 1,500 temporal bones.The normal and the abnormal bones are described and discussed in detail. It would take me too far afield to retell the author's findings or even to summarize them. The article should be read and studied in the original. Suffice it here to call attention to this newer report, particularly of interest to those who desire to correlate their own findings with those of this excellent study.The exact location of a suppurative lesion within the tympanic cavity is always useful from the practical, bedside standpoint. Vahldieck's2 treatise is therefore noteworthy. He substantiates prior observations made by Wittmaack and gives data useful in estimating the outcome of a case of otitic suppuration. Every one is becoming more exact in making prognostic estimations of the outcome of a given case of otitic suppuration. A factor in arriving at this decision is naturally a knowledge of the bony structure on which the lesion has developed. Another factor finds its expression in Vahldieck's report, in which he reiterates the value to be placed on the different forms of otitis which present themselves for observation. Thus, for example, retrotympanic suppuration usually becomes basically chronic. In an earlier publication I3 called From the Department of Otolaryngology of the Beth Israel Hospital.