112 Proceedings of the Eoyal Society of Edinburgh. [Sess. 
The existence of fossil fungi has been a matter of knowledge for many 
years. The earliest reference is contained in an important article con- 
tributed by Worthington Smith (10) to the Gardeners Chronicle in 1877, 
in which he says : “ Mr Darwin informs me that fungus threads in a fossil 
state were shown to him in silicified wood, more than forty years ago, by 
Mr Brown.” The first actually to describe fossil fungi was Unger (11), 
who wisely classified them under the general name of Nyctomyces. 
Worthington Smith’s paper gives the first fairly complete account of a 
fossil fungus. He found, in the British Museum, a slide which had been 
cut from the vascular axis of a Lepidodendron, and which, under the 
microscope, showed abundant traces of an organism which he called 
Peronosporites antiquarius. Not only the hyphm but also the repro- 
ductive organs were shown with great clearness. The same organism was 
subsequently examined by Williamson (13), who, though unable to confirm 
Smith’s statement that the hyphse were septate and that the oogonia con- 
tained oospheres, was, however, able to confirm the existence of hyphse and 
of oogonia attached to the hyphse, and further stated that the spheres 
which were found in the slide were the spores of the same organism. He 
gives their measurement and figures the first stages of their germination. 
Whilst with regard to this species there is some uncertainty concerning 
some of the smaller details, there is no doubt as to its fungal nature ; and 
inasmuch as its fungal nature, reproductive organs, and reproductive cells 
have been figured, described, and measured, it constitutes the best known 
of the fossil fungi. Renault (6) describes under the name Oochytrium 
Lepidodendri, a filamentous fungus which was endophytic in the cavities 
of the scalariform tracheides of Lepidodendron. The hyphm are slender 
and branched and bear numerous sporangia. They were assigned to the 
order Chytridinem. In this case also the description is fairly complete. 
The most valuable work on this subject appeared in 1894 from the pen 
of Felix (2). The following fossil fungi are mentioned in his list : — 
Ascomycetes. 
1. Perisporiacites Larundae. 2. Leptosphaerites Ligeae. 
3. Chaetosphaerites bilychnis. 
Hyphomycetes. 
1. Trichosporites Conwentzi. 3. Haplographites xylophagus. 
2. Haplographites cateniger. 4. Cladosporites bipartitus. 
5. Dictyosporites loculatus. 
Hymenomycetes. 
1. Agaricus melleus fossilis. 2. Spegazzinites cruciformis. 
