ii4 The Scottish Naturalist. 



lore or dictation. The wonderful way in which dense masses 

 of stratified rocks are broken up and turned aside by erupted 

 material can in no way be realized excepting by that of ob- 

 servation. 



To assert without due deliberation that any patch of rocks is 

 of such or such an age, or was deposited or erupted under 

 these or those conditions, is to be at least irreverent. To de- 

 clare upon them at all, even after careful scrutiny, is serious 

 enough. One's own opinions, nursed up within one's self, may 

 be very self-satisfying, but it is perhaps a duty to submit 

 such opinions — at least upon subjects in the Natural world — 

 to the scrutiny of one's fellow-men, though often the result 

 is mortifying to our vanity ; and yet how seldom do we hesitate 

 to put our opinions to the test. 



I have thought seriously about certain beds in the Earn 

 Valley, and have certain beliefs in connection with them, but 

 that they will be accepted as at all admissible I am not at all 

 sure. My endeavour has been to place these beds in their 

 exact chronological position, and in this endeavour I have been 

 inadvertently led to associate them with Dunning of intemperate 

 coal-boring notoriety. Hugh Miller says — " Old Red Sand- 

 stone," p. 198, — "The Sandstones of Strathearn and the Carse 

 of Gowrie yield their plates and scales of Holoptychius, the 

 most abundant fossil of the Upper Old Red." Taking this cue, 

 I have searched among the sandstones of the Earn for something 

 indicative of their age, but have been quite unsuccessful. I ob- 

 tained a fine scale and some appendages of Holoptychius from 

 Clashbennie, in the Carse of Gowrie. Nevertheless my first ac- 

 quaintance with these rocks increased my belief in their asserted 

 age, for their lithological character bore a generally universal 

 contrast to the New Red Sandstone area around Liverpool, 

 which I had previously carefully examined; and I have now full 

 faith that these rocks are indeed Old Red. From Auchterar- 

 . der to Abernethy on the south, and all along the north side of 

 the valley for the same distance, I have seen nothing to belie 

 this belief except at Dron. These said beds took me altogether 

 by surprise. Their very aspect spoke of something new ; that 

 on the first day's exploration appeared in the shape of a small 

 ganoid scale and one or two conchiferous shells. 



The beds are situated at East Dron, and are best exposed 

 about 50 yards south of the mill, where they form a cliff at the 

 side of the burn, 16 or 20 feet in height, capped by Boulder Clay. 



