It is only recently that great importance has been attached to the study of benign lymphogranulomatous syndromes. In France, Germany, Italy and other countries, Durand, Nicolas and Favre's¹ demonstration of the existence of a new venereal disease has received especial attention, the more so after W. Frei² established, in 1925, the diagnostic importance of his intracutaneous reaction with an antigen prepared from lymphogranulomatous lesions.

A frequent increase in the number of cases and a more extended use of the intracutaneous reaction of Frei have proved that this biologic test is not always specific. Owing to this fact, numerous diagnostic errors are made.

After experimental and clinical investigations, we have arrived at the conclusion that these errors are due to the fact that among the different symptoms ascribed to Nicolas and Favre's disease, there exist two different diseases which give a positive reaction only when the proper antigen is