OF ARTS AND SCIENCES. 205 



VIII. 



CONTRIBUTIONS FROM THE CRYPTOGAMIC LABORATORY OF 

 THE MUSEUM OF HARVARD UNIVERSITY. 



VI. — ON THE MORPHOLOGY OF RAVENELIA 

 GLANDULiEFORMlS. 



By G. H. Parker. 



Presented June 16, 1886. 



At the sucrcrestion of Dr. W. G. Farlow, in the fall of 1885, the 

 writer commenced some investigations upon the leaf fungus known as 

 Ravenelia glandulceformis, Berk, and Curt., and through the kindness 

 of Mr. H, W. Ravenel an abundance of carefully selected material 

 was placed at his disposal. This consisted of the dried leaves of the 

 host plant, Tcphrosia virginiana, Pers., which had been collected in 

 1879 at Aiken, S. C, by Mr. Ravenel, with the especial object of 

 securino- a series of the principal stages in the development of the 



fungus. 



As may be seen from the literature of Ravenelia, our knowledge 

 of this fungus is as yet incomplete, and questions of morphological 

 interest concerning it are still unsettled. The object of this paper is 

 to deal with one of these questions, namely, the morphology of the 

 teleiitosporic sta^^e. 



The young leaflets of Tejyhrosia show numerous dingy orange- 

 colored spots scattered over both their upper and lower surfaces. 

 These spots as a rule are more frequently met with below than above. 

 On closer examination each spot is seen to consist of from one to 

 several roundish or elongate swellings in the epidermis of the leaflet, 

 the individual swellings often being ruptured above, and showing a 

 cavity entering the tissue of the leaf. Usually, large clusters of such 

 swellings on the lower surface of the leaflet are accompanied by several 

 corresponding swellings on the upper surface, and almost invariably 

 where swellings thus occur both above and below, the lower group is 

 much the larger. 



A transverse section of a leaflet in the region where the swellings 



