Gcniiiiiatiou of Tclctitospores of Ustilaginecc. 85 



size of 15 — 18 X 3'5— 4'5a'- They formed an opalescent 

 cloud at the bottom of the culture-drop. Each promy- 

 celium was cylindrical in form, vacuolate, and eventually 

 became triseptate, and produced promycelial spores both 

 laterally and also at either end (Plate VII. Figs. 22, 24, 25). 

 The latter were elliptical in form, and measured from 

 3 to 4/^< in length by 2}i in width. Many of the promycelia 

 were observed to be slightly curved. 



U. utriculosa (Nees). — The teleutospores of this species 

 are by no means easy to germinate, and although I have 

 made a great man)- attempts to do so, I have always 

 failed. Schrbter* states that they emit a cylindrical promy- 

 celium, which becomes triseptate, and produces elliptical 

 promycelial spores in pairs, which conjugate in couples. 



SpJiacelotJieca. — The spores do not germinate at all 

 readily, and I have been unsuccessful in observing the 

 process. Schroter f states that the teleutospores emit a 

 cylindrical promycelium, which becomes triseptate, and 

 bears elliptical promycelial spores laterally, and that these 

 conjugate in pairs at their bases.} 



Sorosporiuni. — Woronin§ succeeded in getting the spores 

 of 5". saponarice, Rud. on Lychnis dioica and Saponaria 

 officinalis to emit a germ-tube, but no spore-formation was 



* Schroter, Cohn's " Krypt. Flora von Schlesien," vol. iii. p. 273. 



t Loc. cit., p. 275. 



X The two following species of Ustilago can in no sense be regarded as 

 being British, yet they occur in this country sufficiently commonly to render 

 them objects of interest. 



U.pcuum, Richdt., is often met with on the cheaper kinds of figs, known 

 in the trade as "natural figs." The spores are formed in the interior of the 

 fruit, and are black or dark violet, smooth, globose, from 6 to 8/i across. I 

 found no germination took place below 10° C, but between 10° and 13° C, 

 when placed in water, they emitted promycelia 20 — 150 X 4 — 5^, but I was 

 unable to observe any further development. 



U. phcenids, Corda, is a closely allied species, which is frequently to be 

 met with on cheap dates. The spores are globose, smooth, dark violet, 

 from 4 to 5,u in diameter. 



§ W'oronin, Icr. cit., pp. 18, 19, t. iii. figs. 13-18. 



