LETTER TO A CHILD. 311 



lapped by it. This, he at once said, on ascertaining the 

 fact, cannot be the upper side of the Pterichthys. A 

 plate so arranged would have formed no proper pro- 

 tection to the exposed dorsal surface of the creature's 

 body, as a slight blow would have at once sent it in 

 upon the interior framework ; but a proper enough one 

 to the under side of a heavy swimmer, that, like the flat 

 fishes, kept close to the bottom; a character which, as 

 shown by the massive bulk of its body, and its small 

 spread of fin, must have belonged to the Pterichthys. 

 Sir Philip followed up his observations on the central 

 plate by a minute examination of the other parts of the 

 creature's armature ; and the survey terminated in a 

 recognition of the earlier restoration, set aside so long 

 before, as virtually the true one ; a recognition in 

 which Agassiz, when made acquainted with the nature of 

 the evidence, at once acquiesced. 5 This is the kind of 

 fact which proves consummate practical ability of that 

 character which cannot be derived from books. 



We may here take in a letter written by Miller, 

 about the time when the Old Red Sandstone was getting 

 into circulation as a book, to a little boy whom he had 

 known in Cromarty. It contains a few details as to his 

 history at the time which cannot be presented to the 

 reader so pleasantly in any other way, and it adds one other 

 illustration to the many we have already had of his 

 gentle, playful, sympathetic manner with children. 



'Edinburgh, 5, Sylvan Place, Sept. 8, 1841. 

 'MY DEAR AlJE MUNRO, 



' I will tell you how it was that I did not reply 

 to your kind letter last spring. It was all in consequence 

 of another letter which I received only two days after I 

 received it, and which entirely put it out of my mind for 



