This paper describes a series of experiments that were performed in dogs, attempting to reproduce in the laboratory a chronic granulomatous reaction of the larynx. The purpose of this work was to learn about the possible pathogenesis of these lesions and to find the reasons behind their chronicity and recurrence. The practical aspects of this research were to formulate and, hopefully, to develop reasonable diagnostic and therapeutical approaches that could be used in the treatment of patients. The positive and negative results of these experiments indicate that the granulomatous response is probably influenced not only by external factors, but also by intrinsic factors. Clinically these findings led to the concept of not circumscribing judgment to the peripheral changes only, but to the assessment of all facts surrounding each individual case.