FOREIGN WORK AMONGST THE OLDER 



ROCKS. 



FOREIGN workers amongst the older rocks have 

 written a number of books and papers published 

 during the earlier part of the year 1894. Much of the 

 literature consists of a description of local details, more or 

 less valuable, which will eventually be fitted into their places 

 in the great geological puzzle, though at present they lie 

 unused, as their connection with those parts of the puzzle 

 which have been pieced together cannot be traced. In 

 other papers we find pieces which can be fitted, and in 

 others again evidence of pieces formerly supposed to have 

 been assigned to their right positions which must be re- 

 moved and placed elsewhere. 



The work here noticed is concerned with Precambrian 

 and Palaeozoic rocks. The principal task amongst the former 

 rocks is the gradual removal of rock-masses from the group 

 of rocks whose origin is unknown to that whose mode of 

 production is known or inferred. The work in the 

 Palaeozoic rocks is instructive. Detailed work again and 

 again proves the value of fossils as means of identifying 

 strata, and clears up difficulties that have arisen from too 

 hasty examination of strata, whilst as a result of rapid work 

 we are furnished with new difficulties, explained away by 

 the handy theories of colonies and migrations. As the 

 laborious worker in a district of a few score square miles 

 breaks down case after case upon which the advocates of 

 these convenient " refuges for the stratigraphic destitute," 

 as they have been termed, rely, the lightning-stratigrapher, 

 traversing half a continent, produces fresh instances, which 

 will in turn doubtless disappear. Whilst alluding to this 

 subject it is satisfactory to call attention to a remark made 

 by Sir William Dawson showing that plants, as well as 

 animals, when properly studied, give no countenance to the 

 existence of anomalous "colonies". He says(i): "Each 

 geological period was sufficiently long to permit plants to 



