Throughout the southeastern United States the foliage of trumpet creeper, Tecoma radicans (L.) Juss., is commonly attacked by the imperfect fungus Cercospora sordida Sacc. This organism was first known to mycologists about 1880, from collections made in Georgia by H. W. Ravenel, who sent specimens to P. A. Saccardo for identification. He, in turn, described it in Michelia, in 1880, and illustrated it the following year in Fungi italici. Subsequently this fungus is listed from collections in New Jersey by J. B. Ellis (Ellis and Everhart, 1885), in Alabama, by G. F. Atkinson (1891), and in Texas, by F. D. Heald and F. A. Wolf (1912), and is among their exsiccati. These facts and other pertinent information on Cercospora are contained in the comprehensive accounts of Solheim (1929) and Lieneman (1929). The present studies, extending over a period of years, are herein recorded as a part of series of observations by the writer on the life history and development of imperfect fungi having perithecial stages that are initiated by spermatia and ascogonia. Some of these observations, involving species of Cercosporella, Lecanosticta, Marssonia, Polythrincium, Ram.ularia, Septocylindrium, Septoria, and Cercospora, have already been published, but a considerable number of others, as yet unpublished, clearly establish that spermatia and ascogonia are precursors of the ascogenous stage.