READING RIDDLES OF THE ROCKS 121 



For the adjustment of the muscles is depend- 

 ent on the structure of the skeleton, and put- 

 ting on the muscles means blocking out the 

 form, details of external appearance being sup- 

 plied by the skin and its accessories of hair, 

 scales, or horns. Let us suppose in the present 

 instance that we are dealing with one of tlie 

 gi-eat reptiles known as Triceratops whose re- 

 mains are among the treasures of the National 

 JNIuseum at Washington, for the reconstruc- 

 tion of the big beast well illustrates the meth- 

 ods of the palaeontologist and also the troubles 

 by which he is beset. JNIoreover, this is not a 

 purely imaginary case, but one that is very 

 real, for the skeleton of this animal which was 

 shown at Buffalo was restored in papier-mache 

 in exactly the manner indicated. We have a 

 goodly number of bones, but by no means an 

 entire skeleton, and yet we wish to complete 

 the skeleton and incidentally to form some 

 idea of the creature's habits. Now we can in- 

 terpret the past only by a knowledge of the 

 present, and it is by carefully studying the 

 skeletons of the animals of to-day that we can 

 learn to read the meaning of the symbols of 



