YEETEBEATA. 



271 



cannot be mistaken for either. By microscopic examination 

 we are thus enabled to show that the physiological laws 

 relating to the structure and growth of bone have ever been 

 the same from the first creation of vertebrate animals in the 

 far remote period, when fishes were introduced into the seas 

 of the Silurian and Devonian eras, down to the present hour; 

 that the colossal Iguanodon was provided with bone-cells 

 formed after the same type as the tiny lizard that crosses 

 our path ; that the bones of the gigantic Dinornis exhibit 

 110 diiference in structure from those of its representative, 

 the Artery x ; that the bones of the Mastodon and Megathe- 

 rium those terrestrial giants of the pre- Adamite earth are 

 modelled after the type which we see in our domestic quadru- 

 peds, and in man himself. 



The following table, from the above-mentioned paper,* 

 shows the measurement of the bone-cells in Pishes, Reptiles, 

 Birds, and Man. 



MEASUREMENT OF THE BONE-CELLS IN PARTS OP AN ENGLISH INCH. 

 (Transverse sections.) 



HUMAN 



OSTRICH 



TURTLE 



CONGER EEL 



f Long diameter 



Short diameter 



Long diameter 



Short diameter 



j" One of the largest 

 \ One of the smallest 



f One of the largest 



\ One of the smallest -g^-Q 



Long diameter 



Short diameter 



j Long diameter 



I Short diameter 



f One of the largest 



\ One of the smallest g%- s -Q 



J One of the largest s ^ 

 \ One of the smallest 3-^50" 



f One of the largest -g^ 

 \ One of the smallest y^ 



J One of the largest 



\ One of the smallest -g-^o 



{One of the largest -g-t^ 

 One of the smallest ^ 3 -g 



{One of the largest 

 One of the smallest s $ i - ff 



* Transactions cf the Microscopical Society, vol. ii. partii. p, 46. 



