SlG ANNUAL REG 1ST ER, 1794. 



crust, in which, however here and 

 there bones nre seen sticking. And 

 here ends this connected series of 

 most remarkable osteolithical ca- 

 verns, as tar as they have been lii- 

 therto explored ; many more may, 

 for what we know, exist, hidden, 

 in the same tract of hills. 



Mr. Esper has written a history 

 in German of these caves ; and 

 given descriptions and plates of a 

 great number of the fossil bones 

 which have been found there. To 

 this work we must refer for a more 

 particular account of them. 



Olservations on thefnssil hones pre- 

 sentci to the Roijal Societij by his 

 most serene highness the margrave 

 tifAnspachy^c. By the In te John 

 Hunter, esq. F. R. S. Comnm. 

 jiicated by Euerard Home, esq. 

 F. R. S. From the same. 



THE bones, which are the sub- 

 ject of the p.-csent paper, are 

 to be considered more in tiie light 

 of incrustations than extraneous 

 fossils, since their external surface 

 has only acquired a coverinjj of 

 crystallized eartli, and little or no 

 change has taken place in their 

 internal structure. 



The earths with which bones are 

 most commonly incrasted are the 

 calcareous argillaceous, and silice- 

 ous, but principally the calcareous ; 

 and this happens in two ways ; one 

 the bones being immersed in water 

 in which this earth is suspended ; 

 the other, water passing through 

 masses of this earth, which it dis- 

 solves, and afterwards deposits up- 

 on bones which lie underneath. 



Bones which are incrusted seem 

 never to undergo this change in the 

 earth, or under the water, where 

 the soft parts \wre destroyed ; white 

 bones that are fossilized become so 

 in the medium in which theywevc- 

 de]>osited* nt the animal's death 

 The incrusted bones have been pre- 

 vinusly exposed to the open air; 

 this is evidently the case with tlie 

 bones at present under considera- 

 tion, those of the rock of Gibraltar, 

 and those found in Dalmatia ; and 

 from the account given by the abbe 

 Spallaiizani, those of the island of 

 C'erigo are under the same circum- 

 stances. They have the characters 

 of exposed bones, and many of 

 them are cracked in a number of 

 places, particularly the cylindrical 

 bones, similar to the effects of long 

 expo.iure to the sun. This circum- 

 stance appears to distinguish them 

 from fossilized bones, and gives us 

 some information respecting their 

 history. 



If their numbers had correspond- 

 ed with what we meet with of re- 

 cent bones, we might have been 

 led to some opinion of their mode 

 of accumulation ; but the quantity 

 exceeds any thing we can form an 

 idea of. In an inquiry into their 

 history three questions naturally 

 arise : did the animals come there 

 and die ? or were their bodies 

 brought there, and lay exposed; or 

 were the bones collected from dif- 

 ferent places ? The first of these 

 conjectures appears to me the most 

 natural ; but yet I am by no means 

 convinced of its being the true one. 

 Bones of this description are 

 found in very dilFerent situations, 

 which makes their present state 



• Bones that have been buried with the flesh on acquire a stain which they never 

 lose ; and those which have been long immersed ia water receive a considerable tinge. 



mot* 



