A PHYLLACHORELLA PARASITIC ON 

 SARGASSUM 



C. Ferdinandsen AND 6. WlNGE 



In March, 1914, Professor C. H. Ostenfeld collected a quantity 

 of Sargassum in the Atlantic at a locality lying at 30 0 21 1 N. Lat., 

 45 0 20 1 W. Long. Two of the plants had conspicuous protuber- 

 ances, which were scattered along the stems and partly on the 

 bladders as well. These protuberances varied in size; being 

 sometimes as large as the head of a pin and sometimes ^2-1 cm. 

 across, irregularly rounded and knobby (Fig. 1). The knobby 

 surface of the tumors was due to perithecia-like loculi, sometimes 

 placed close together in a continuous stroma, giving a black color 

 to the tumor; sometimes more scattered, the stroma not being 

 continuous but divided into several minor stromata containing 

 only a single or but few loculi. In the latter case the pale tissue 

 of the host was visible between the small partial stromata. 



Fig. 1 (On the left). Showing the habit of the fungus, slightly magnified. 

 Fig. 2. Stroma with two loculi. X 15. Asci and spores. X 160. 



A further investigation revealed the fact that the parasitic 

 organism was a well-developed ascomycetous fungus, belonging 



102 



