422 ON THE GEOLOGICAL RELATIONS 



any other manner, from cemented fragments, such as 

 the organic rocks of Gibraltar and of Dalrnatia, 

 abound in the remains of terrestrial animals, as the 

 Travertines often contain vegetable and terrestrial 

 shells. If, lastly, I may include among the alluvial 

 deposits, those loose substances found in caverns, 

 these are also the frequent notorious repositories of 

 some of the most remarkable animal remains which 

 have been discovered. Arriving above the later gravel 

 and sand; and at the peat, the fossil remains intro- 

 duce us to our own living world. And thus also are 

 we introduced to it by the fossil shells of recently 

 drained or existing lakes, and by those terrestrial and 

 superficial deposits of shells, resembling soft chalk 

 intermixed with these objects, the existence and na- 

 ture of which I first pointed out in Perthshire, to 

 those who have> many years afterwards, made the 

 " original discovery." The celebrated human ske- 

 letons of Guadaloupe are the same geological fart in 

 another form : a recent oolithe is but an indurated 

 alluvium. 



Of the Order of Succession and relative Antiquity of 

 organic Fossils. 



It has been supposed that a certain order existed 

 among the species of organic fossils, under relations 

 to a definite succession among the strata ; but this 

 includes two points of considerable importance, the 

 one relating to the organic creation itself, the other 

 to its geological relations. The last will form a se- 

 parate section hereafter. 



I shall not insult the common sense of the reader 

 by retailing the dreams of writers respecting organic 

 molecules and the gradual improvement of species. 

 For this miserable progeny of an atheistical Greek 



