62 MINNESOTA r.OTANICAL STUDIIiS. 



of a Tremclla and were so laree that they extended in folds over the 

 si;rroun(hnf^ chips and earth in which tlie CoUybia was grovving^. 

 ( hie mass was four inches in (hameter. The CoUybia was growing 

 abundantly among the decaying debris of a large water soaked log 

 and was covered over with the white convoluted mass of Exobasid- 

 ium. 



Peck and Atkinson have both described this fungus from New 

 York collections under the genus Tremclla. Peck's ^ picture agrees 

 perfectly with some of the very young masses of the Minnesota ma- 

 terial, while Atkinson's - picture agrees with some of the slightly 

 older stages. Burt ^ has published a more complete description from 

 material collected in Vermont under the title, "Structure and Nature 

 of Tremella mycctophihim Peck." He has clearly pointed out the 

 structural characters of the basidia which separate this from the 

 Tremclla type and has placed it in the genus Exobasidium. The 

 Minnesota specimens distinctly confirm this classification but the 

 basidiospores are very much smaller and more nearly spherical in 

 shape than those described by Burt. In the mature Minnesota ma- 

 terial the spores are not more than 2-3 mic. in diameter and nearly 

 spherical (PI. XIII. Fig. 4, 6). In fact they agree more nearly with 

 Burt's conidia than with the basidiospores. As they are repeatedly 

 found attached to the basidia, there can be no doubt as to their 

 origin. 



The fungus does not appear to form a true gall, although it ap- 

 pears to be a true parasite. There seems to be no hypertrophy of the 

 host although it is sometimes difficult to distinguish the hyphae of 

 the host from those of the parasite. The attachment to the host is 

 very slight, especially on the stipe (PI. XIII. Fig. 5) where it grows 

 just as abundantly as on the cap. On the stipe the fruiting body 

 seems to be merely pushed out between the hyphae of the host, 

 thence swelling out into a hollow convoluted mass. The hyphae 

 are smaller and more finely granulated generally, than those of the 

 host plant and are from one-half to one-quarter as wide. Clamp 

 connections are found only among the coarser sterile hyphae below 

 the hymenial layer. 



iPeck N. Y. Mus. Report 28:53, pi. 1. f. 4. 1879. 



' Atkinson, . . "Mushrooms Kdible, roisonoiis & eto." p. 205. 1900. 

 »Burt. E. A. Bull. Torr. Hot. CI. 28:285-287. pi. 23. 1901. 



