48 THE LESSON OF EVOLUTION 



announced that a gigantic foraminifer, which they 

 called Eozoon, had been discovered a few years pre- 

 viously in the Laurentian rocks of Canada ; but the 

 announcement, at first received with favour, has, as I 

 shall presently explain, fallen into discredit. Other 

 discoveries, however, have proved more satisfactory. 

 So far back as 1864 Mr E. Billings found fossils in 

 Newfoundland, which both he and Sir W. Logan 

 thought at the time to be Cambrian, but which have 

 since (in 1888) been shown to be pre- Cambrian. In 

 1 883, and again in 1890, Professor Walcott announced 

 the discovery of undoubted organic remains in the 

 pre-Cambrian of Arizona. In 1889 Dr G. F. Mathew 

 read a paper to the Royal Society of Canada on some 

 lower Cambrian fossils from New Brunswick, which 

 are now, like those from Newfoundland, considered to 

 be pre-Cambrian. Also, in 1892, Dr C. Barrois dis- 

 covered supposed radiolarians and sponge-spicules in 

 the pre-Cambrian rocks of Brittany, descriptions of 

 which were published in 1895 by Dr Cayeux. 



Here, at last, we seem to have reached a palseon- 

 tological base ; for although radiolarians and sponges 

 are not the lowest of animals, they are the lowest 

 which contain any hard parts capable of being pre- 

 served, and are, therefore, the lowest in organisation 

 of any animals we can hope to find fossil. Their 

 position too is, probably, in the oldest system of rocks 

 in which we can ever hope to recognise fossils ; and 

 they are, no doubt, as old or older than any other 

 known organisms. Consequently, the palseontological 

 sounding-line appears to have touched the bottom. A 

 glance at what we know, or what we may legitimately 

 surmise, about the early history of the earth will help 



