TRANSACTIONS OF SECTION K. 



729 



Experiments on Lemna minor growing in Detmer's culture solution show that 

 the purer auximone silver fraction is more effective on growth than the cruder 

 phosphotungstic fraction. Six glass dishes, each containing thirty Lemna 

 plants, were arranged in three series of two dishes each : A. Detmer's culture 

 solution ; B. Detmer+phosphotungstic fraction (17 parts per million) ; C. Detmer 

 + silver fraction (OSo parts per million). The average total area of thirty 

 plants was 112 sq. mm., giving an average area of 37 sq. mm. per_ plant. The 

 average results of growth each week in the two dishes of each series are given 

 in the following table : 



7. On Fossil Fungi and Fossil Bacteria. 

 By Dr. D. Ellis. 



An investigation of the ferruginous and fossiliferous rocks of Great Britain 

 showed that some of the organic fragments in the ferruginous rocks had been 

 in a state of putrefaction when engulfed. A study was made of the micro- 

 organisms which were responsible for this putrefaction. 



I. A fossil fungus was found in the Frodingham Ironstone of Lincolnshire 

 (Lower Lias). To this organism the name Phycomycites Frodinghamii has been 

 given. 



Characteristics. — Hyphse of two dimensions, namely, 2 fi and 3^ yu respec- 

 tively. The two sizes of hyphse were found in organic connection. There were 

 no traces of transverse walls. In addition to the ordinary alternate branching 

 whorls of hyphffi arising from the same level were frequently observed. In many 

 places the threads showed thickening cushions. Some of these were appa- 

 rently in association with the formation of branches and were of a supporting 

 nature ; others, however, had no apparent significance. 



Some of the hyphse had terminal dilatations of a sporangial nature, as in a 

 few cases spore-like bodies were enclosed in them. The sporangia measured 

 about 24 n (j\j mm.) and were roughly spherical. The spores were 10 n in 

 diameter. Probably each sporangium normally enclosed four spores. The 

 fungus, unlike all modern fungi, had a power of attraction for iron-compounds, 

 and in all cases its hyphse were covered with a varying quantity of ferric 

 hydroxide. 



II. A fossil fungus was found in the Secondary Eocks in the Island of 

 Eaasay (N.W. Scotland). This fungus had the same general characteristics as 

 the preceding, only its hyphse were covered with a hard black membrane of a 

 carbonaceous nature. No sporangia were discovered. It is proposed in the 

 meantime to call this organism Palseomyces o. 



III. In the Ferruginous Limestone of Dunliath (Inferior Oolitic Series of the 

 Jurassic Rocks) a fossil Actinomyces was discovered. This micro-organism was 

 found as a thick meshwork of minute threads inside fossilised animal fragments. 

 The threads measured "75 fi to I'D /j. across and branched freely. It is proposed 

 to name this micro-organism Actinomycites u. 



IV. From nodules derived from the base of the Gault at Folkestone fossilised 



