IN presenting this subject, it is our earnest desire to stimulate more interest, in an undeveloped branch of medicine and surgery in infants and children, and to show its value to those concerned. Your attention is called to some of the outstanding—yet small—number of men in this country. who have made a study along these lines, namely, Hyman, Hinman, Stevens, Kretschmer, Beer, and a few others, including Patch, of Montreal. The study of diseases of the urinary tract in infancy and childhood is receiving more and more consideration, and, as a result, great progress is being made in the recognition of these conditions in the young. Until the small caliber cystoscopes had been perfected, no real progress was made; a decade ago cystoscopy was considered rather a cruel procedure, hence no attempt was made to examine these young subjects in an efficient manner, as was done in the adult. Very little to-day is said in text-books regarding the radiological study of urinary diseases or the diagnostic value of cystoscopy, radiography, or cystography. These possibilities were first pointed out by Nitze in 1907 and Beer in this country in 1911, and by Kretschmer and Helmholtz later. Such a co-operation between the urologist and roentgenologist is essential to the development and advancement of our methods of diagnosis. For a long time it was considered that all we could do was to show a calculus, but by the development of the small cystoscope, opaque catheters and media, many pathological evidences have been shown on the film, and with the further development of our Bucky diaphragm and cystoscopic tables with radiographic equipment, this method of diagnosis has become less complicated. We realize that this subject should be strictly a radiological one, but we are so closely associated with the urologists that their help must also be enlisted. In fact, no branch of medicine can be properly studied without due consideration to the clinical history, and especially in the case of the young, one must consider the laboratory and cystoscopic findings, which are as important to us as our X-ray evidence is to the urologists. We must not lose sight of the fact that this co-operation goes far in the evaluation of the clinical picture. We must keep in mind the various contours produced by pathologic conditions and how to interpret symptoms as well as shadows on the films. We have to consider the disturbances of micturition, dysuria, frequency, enuresis, hematuria, pyuria, pain and swelling in one or both kidney regions. For instance, dysuria, with frequency, may be caused by Bacillus coli infection, urinary tuberculosis, calculus, or foreign body. When one reads that pyuria shows a mortality of from 10 to 18 per cent, it behooves all concerned to study these cases, both in adults and children. In cases of chronic pyuria, we must look for a cause of the suppuration, as malformation, calculi, tuberculosis, tumor, abscess, hydro- and pyonephrosis.