32 Transactions British Mycological Society. 



factors upon them, and also as regards crop values. It is not 

 necessary to attend formal classes in agriculture to get the 

 requisite point of view, and in many ways the proper outlook 

 is best inculcated through practical instruction in the field by 

 a competent plant pathologist. It may be thought that I have 

 outlined an ideal impossible of accomplishment ; I do not think 

 so, and having had considerable experience in the training of 

 mycologists, I have not suggested more than is actually attain- 

 able in practice. I have ventured to place this matter before 

 you, because there is a tendency in some quarters to divorce 

 mycology and plant pathology from botany. That I am sure 

 is a profound mistake, and I trust that any tendency in that 

 direction will be resisted to the uttermost in this country. 



LAMPRODERMA COLUMBINUM ROST. 

 AND ITS VARIETIES. 



By G. Lister, F.L.S. 



Lamproderma columhinum (Pers.) Rost. is in its typical state 

 a beautiful and well-marked species. It is distinguished by 

 having ovoid or globose iridescent sporangia on long stalks; 

 dark capillitium radiating from a cylindrical columella and com- 

 posed of acutely branching threads which end in slender colour- 

 less branchlets, and form a dense brush or pile at the surface. 

 The spores are dark purplish-grey, closely spinulose, and ii to 

 14 /x in diameter. This is the usual form, appearing on dead 

 coniferous wood, and widely distributed in temperate regions. 



Two other forms, connected with the typical one by gatherings 

 intermediate in character, and having typical spores, occur on 

 moss or wet rocks, on Sphagnum, and less frequently on fir wood. 



One, which may be named var. brevipes, is not infrequent in 

 this country, and probably on the continent also. The globose 

 sporangia have short and often slender stalks, 0-7 mm. or less 

 in height ; the capillitium in some instances can hardly be dis- 

 tinguished from that of typical L. columhinum, but is usually 

 less dense; in other examples it consists of purplish mottled 

 threads, tubular and flattened near the base, branching re- 

 peatedly and becoming very slender above where they anasto- 

 mose to form an irregular network; in some developments a 

 curious knotted effect is produced by the presence of dark broad 

 expansions in the axils of some of the branches. 



This variety has been obtained many times in a wooded 



