Eozoön

Eozoön, the name given in 1864 by Sir William Dawson to an assumed organism whose remains constitute reefs of rock in the Archæan System (q.v.) in Canada; apparently a large foraminifer, which must have grown in sheets on the seabottom. Occurring as it does in rocks not formerly supposed to be fossiliferous, it would be the oldest known organism, and would deserve its name Eozoön ('Dawn-animalcule') canadense. The late Dr Carpenter strongly maintained the organic nature of Eozoön, but of late years the belief that it is inorganic has gained ground. Messrs King and Rowney were the first in Britain to express this belief. This is likewise the view held by mineralogists and petrologists generally. In 1878 Professor Möbius subjected Eozoön to an exhaustive examination, and came to the same conclusion. He shows that the so-called 'proper-wall' or 'nummeline layer' of the supposed fossil consists simply of fibrous calcite. Under the microscope no 'delicate pores' or fine 'vertical tubes' appear in this fibrous band, but the fibres consist of minute four-sided needle-like prisms, lying close side by side.