READING RIDDLES OF THE ROCKS 117 



of rock, in order that all parts may be pre- 

 served. 



We will take it for granted that our speci- 

 mens have safely passed through all perils by 

 land and water, road and rail ; that they have 

 been quarried, boxed, carted over a roadless 

 country to the nearest railway, and have with- 

 stood 2,000 miles of jolting in a freight-car. 

 The first step in reconstruction has been taken ; 

 the problem, now that the boxes are reposing 

 on the work-room floor, is to make the blocks 

 of stone give up the seCl-ets they have guarded 

 for ages, to free the bones from their envelop- 

 ing matrix in order that they may tell us 

 something of the life of the past. The method 

 of doing this varies with the conditions under 

 which the material has been gathered, and if 

 from hard clay, chalk, or shale, the process, 

 though tedious enough at best, is by no means 

 so difficult as if the specimens are imbedded 

 in solid rock. In this case the fragments 

 from a given section of quarry must be as- 

 sembled according to the plan which has been 

 carefully made as the work of exhumation 

 progressed, all pieces containing bone must be 



