386 Rev. M. J. Berkeley and Mr. C. E. Broome on British Fungi. 



completely charred by the 3un. D. Lichenum, Fr., is probably 

 more nearly allied to D. hymenicola, but in the absence of all in- 

 formation as to the sporidia, it is impossible to speak positively, 



661. Dothidea Johnstoni, n. s. Maculis minutis orbicularibus ; 

 cellulis concentricis semiliberis, ascis brevibus ; sporidiis obovato- 

 oblongis uniseptatis. On the leaves of a small Epilobium, Ber- 

 wick, Dr. Johnston. 



Forming little black spots about a line broad studded with 

 concentric half- free cells with a little round aperture ; there are 

 sometimes a few scattered short stiff brown hairs on the surface,, 

 occasionally converging over the orifice. Asci short, subcylin- 

 drical, generally rather thicker below. Sporidia biseriate, ob- 

 ovate-oblong, at length pale brown, uniseptate. 



Dothidea Epilobii is totally different, and there is no other 

 species with which it can be compared. It has almost the habit 

 of a Depazea, or rather of Sphceria Rumicis. 



*Lasiobotrys Lonicera, Sprengel MSS. ; Kze. Myc. Hefte ii. 

 p. 88. 



After a very careful investigation of this genus, we are enabled 

 to confirm the observations of Dr. Montagne, adding however a 

 little to what he has seen. It is to the specimens published by 

 Desmazieres, no. 957, that we are indebted principally for our 

 information. We have distinctly observed the small bodies found 

 at the base of the larger sclerotioid grains pullulating from them, 

 as seen in our sketch. One or two of the outer cells swell, and 

 become filled with a few hexagonal thick-wailed vesicles. As the 

 cells increase in size the included tissue is multiplied, and the 

 external wall becomes reticulated, exactly after the fashion of the 

 transformation of a cell in the genus Antennaria into a sporan- 

 gium. The bodies now separate from the original parent. At an 

 early stage when squeezed, a loose gelatinous mass of slightly 

 branched, subcylindric, short, thickish threads makes its appear- 

 ance. At a later period they are filled with well-formed cylin- 

 drical, short, thick asci, which may sometimes be found con- 

 nected together at the base as if derived from a common thread, 

 of which the structure observed in an earlier stage of growth is 

 doubtless an indication. A sketch communicated by Dr. Mon- 

 tagne exhibits a structure just intermediate. We have not found 

 6poridia, but the asci are as perfect as in Sph&ria herbarum, and 

 as well developed with a distinct second membrane. This seems 

 to favour M. Desmazieres' view of the larger bodies being a scle- 

 rotioid stroma. Vertical sections of these bodies when mature, 

 and accompanied by their ascigerous offspring, show very clearly 

 that the asci are truly contained in the smaller sacs, which are 

 therefore the true perithecia. All doubt as to their origin is re- 

 moved by the discovery of the mode of their production. The 



