CHAPTER XL 

 MARKINGS, FOOTPRINTS AND FUCOIDS. 



I BELIEVE my attention was first directed to the markings 

 made by animals on the surfaces of rocks, when travelling 

 with the late Sir Charles Lyell in Nova Scotia, in 1842. He 

 noticed with the greatest interest the trails of worms, insects, 

 and various other creatures, and the footprints of birds on the 

 surface of the soft red tidal mud of the Bay of Fundy, and 

 subsequently published his notes on the various markings in 

 these deposits in his "Travels in North America," and in a paper 

 presented to the Geological Society of London. I well re- 

 member how, in walking along the edge of the muddy shore, 

 he stopped to watch the efforts of a grasshopper that had 

 leaped into the soft ooze, and was painfully making a most 

 complicated trail in his effort to escape. Sir Charles re- 

 marked that if it had been so fortunate as to make these 

 strange and complicated tracks on some old formation now 

 hardened into stone and buried in the earth, it might have 

 given occasion to much learned discussion. 



At a later period I found myself perplexed in the study of 

 fossil plants by the evident errors of many palaeobotanists un- 

 acquainted with modern markings on shores, in referring all 

 kinds of mere markings to the vegetable kingdom, and espe- 

 cially to the group of fucoids or seaweeds, which had become 

 a refuge for destitute objects not referable to other kinds of 

 fossils. It thus became necessary to collect and study these 

 objects, as they existed in rocks of different ages, and to com- 



