TORTOISES AND TURTLES. 



21 



bono embedded in skin, many and strange 

 changes have taken place. The order of these 

 changes none can tell, only the result thereof 

 is ours, and this, without exaggeration, may 

 be called startling. When we come to take 



FIG 2. The upper portion of the shell carapace of a tortoise, to show 

 the form and position of the horny plates and underlying bones. 

 The horny plates are indicated on the right hand side, the impres- 

 sion of their edges made upon the underlying bones is shown by 

 dots on the left side. The bones are shown by jagged lines. 



an inventory of the structures pertaining to 

 the outside of these creatures structures which, 

 without previous experience, we might expect 

 to find, since they are found in other reptiles 

 one of the first things to be missed would be 



