92 A. Barclay — A Descriptive List of the Uredinese [No. 2, 



GYMNOSPORANGIUM, Hedwig f. 



I. Gymnosporangium Cunninghamianum, Barclay. 



On Cupressus torulosa, Don. 

 And Pyrus Pashia, Ham. 



For a detailed description of this, the only species of Gymno- 

 sporangium in this region, I must refer the reader to a paper on its life 

 history in the " Scientific Memoirs by Medical Officers of the Army of 

 India," Part V, 1889. 



The aecidial stage I have already described in a former volume of 

 this Journal* under the name G. davariaeforrne, as at that time its 

 characters appeared to me to agree most nearly with those of that 

 European species. Since the discovery of its complete life history, 

 however, I have no doubt that it is a distinct species, and I have re- 

 named it as above. 



The teleutosporic stage on Cupressus torulosa may be described as 

 follows. The teleutospore beds are hemispherical dark brown compact 

 bodies during dry weather, and are formed on the ultimate small 

 branches as well as on twigs of 4 to 5 m.m. in diameter. During moist 

 weather these beds swell up enormously into gelatinous masses, which 

 quickly assume a yellow ochre colour, due to a rapid formation of sporidia. 

 During heavy rain the gelatinous spore masses fall to the ground. 



The teleutospores are slender spindle shaped yellow bodies on long 

 stalks covered with a substance capable of swelling greatly when mois- 

 tened. When the spore becomes detached from the stalk after mois- 

 tening a characteristic disc remains at the place of junction. There 

 is no appreciable constriction at the septum, and the walls are usually 

 uniformly thick, with sometimes a slight thickening at the apex. The 

 spores when scraped off dry beds and examined immediately in water 

 measure 75*6 x 25*2/x. Each cell of the spore has two germ pores near 

 the septum. They germinate very readily in water : a promycelium is 

 formed by each cell, dividing into four parts, each forming a sporidium 

 on stout sterigmata. The sporidia are orange red, oval, measuring from 

 15 X 9 to 22 X 14/A. The formation of secondary sporidia is not un- 

 common. Experimental evidence fully confirmed the genetic relation- 

 ship between these teleutospores and the aecidial form on Pyrus 

 PasJiia. 



* J. A. S. B., Vol. LVI, Pt. II, No, 3, 1887. 



