132 
Proceedings of the Eoyal Society of Edinburgh/ [Sess. 
These are named respectively Bacillus I (Gault), Bacillus II (Gault), and 
Micrococcus I (Gault). 
The organism called Phycomycites Frodinghamii is of further interest 
because the evidence shows that in all probability it had, during its life- 
time, a chemiotactic affinity for iron compounds. In this respect it agrees 
with the modern iron-bacteria, a few algse, and some protozoa, and differs 
from all modern fungi. The existence of this activity has caused the 
Frodingham Ironstone to have become slightly richer in its percentage of 
iron than it otherwise would have been. The contribution of micro- 
organisms to the formation of ironstones is discussed. An examination of 
48 samples from various parts of Great Britain showed that in no single 
case are we able to affirm that the ironstones in question owed their 
existence to the activities of the micro-organisms that were found inside 
them. 
LITERATURE. 
(1) Ehrenberg, Die Infusorienstiercheu als vollkommene Organismen, Leipzig, 
1838. 
(2) Felix, “ Studien tiber fossile Pilze,” Zeitschrift d. geol. Gesell.^ 1894. 
(3) Kendall, The Iron Ores of Great Britain and Ireland, 1893. 
(4) Molisch, (i) Die Pflanzen in ihrer Beziehungen zum Eisen, Gustav Fischer, 
1892; (ii) Eisen haldei'ien, Gustav Fischer, 1910. 
(5) Nicholson and Etheridge, A Monograph of the Silurian Fossils of the 
Girvan District in Ayrshire, Edinburgh, 1880. 
(6) Renault, “ Recherches sur les Bacteriacees fossiles,” Annates des Sciences 
Naturelles, 1896. 
(7) Rothpletz, “ Fossile Kalkalgen aus der Familien der Codiaceen,” Zeitschrift 
der deutsch. Geol. GeselL, vol. xlii, 1891. 
(8) Senft, Sy7iopsis der Mineralogie und Geologie, 2 Abth., 1876. 
(9) Seward, Fossil Plants, vol. i, Cambridge University Press, 1898. 
(10) Smith AVorthington, “A Fossil VQYonos,gom (^Peronosporites antiguarius)f 
Gardener’s Chronicle, 1877. 
(11) Unger, Genera et species plantarum fossilium, Vienna, 1850. 
(12) Weiss, “A Mycorhiza from the Lower Coal Measures,” Annals of Botany, 
1904. 
(13) Williamson, W. C., Philosophical Transactions of the Royal Society, 1881. 
