X PREFACE. 



On this it is useless to offer any remarks, as the 

 principle will be found sufficiently detailed in the 

 body of the work. 



5. The specific differences in reliquia depend 

 on the specific differences of form in the original 

 bodies One species of plant or animal can give but 

 one real or genuine species of extraneous fossil. 



The* present positions naturally result from 

 those before advanced For, if the essence of the 

 reliquium be an organic form, its other affections, 

 arising from substance, mode, and soil, are acci- 

 dental, and cannot be used as specific distinctions, 

 which must always depend on something essential 

 to the body, we wish to discriminate. Form, there- 

 fore, must furnish the specific differences of 'reliquia; 

 and it follows, that there will be as many genuine 

 species of reliquia, as there are genuine specific 

 forms in the animal and vegetal prototypes; and, 

 that the number of fossil species are not increased 

 by a separation of parts, or other accidental circum- 

 stances to which the original bodies may have been 

 subjected, during the translation of their forms into 

 the fossil kingdom. 



I am fully aware of the impediments4 that will 

 be thought to oppose the general application of the 



