56 



CARBONIGENOUS ERA. 



more than one place in England, they further bear impressions 

 of rain-drops which have fallen upon them the rain, of course, 



Slab of Sandstone (new- red], showing impressions of 

 rain-drops, and foot-print of bird. 



of the inconceivably remote age in which the sandstones were 

 formed. In the Greensill sandstone, near Shrewsbury, it has 

 even been possible to tell from what direction the shower 

 came which impressed the sandy surface, the rims of the marks 

 being somewhat raised on one side, exactly as might be ex- 

 pected from a slanting shower falling at this day upon one of 

 our beaches. These facts have the same kind of interest as 

 the season-rings of the Craigleith conifers, speaking of the 

 identity of the familiar processes of nature in those early ages 

 with those of our own. 



Hearing of memorials of this kind will prepare the reader to 

 learn that the earliest intelligence we have respecting land- 

 walking animals consists, in great part, of their mere footsteps, 

 impressed on the wet sand or mud which afterwards became 

 rock. Let no one undervalue such testimony. The fidelity of 



