396 Scientific Intelligence. — Geology. 



caves, and especially in those containing bones, where these in- 

 crustations often cover the organic remains. By digging at the 

 distances of J^OO and 400 yards from the entrance, there have 

 been discovered, beneath several layers of marl, which appear to 

 be of a much more recent formation than that of the red clay, 

 the remains of pottery^ which, in its colour and nature, presents 

 the greatest resemblance to the potteries which are found, 

 though rarely, in some ruins, and in some deposits of modern 

 alluvia, and which, from the nature of their paste, their colour, 

 form, and other circumstances, are referred to the times prece- 

 ding the introduction of Roman arts among the Gauls. 



14. On Coral Islands. — According to Linnaeus and Ellis, 

 the calcareous zoophytes, such as the tubipores, milJepores, and 

 madrepores, are inhabited by animalcules, which have some af- 

 finity to the nereids, medusae, and hydrae ; but more recent in- 

 vestigations have shewn, that all the corals which form rocks, 

 or Saxige7ious lithopJiyies of the French zoologists, and even 

 the Pavonia Caryophyllea and the Nullipora of Lamarck, serve 

 as a habitation to gelatinous mollusca of a particular kind, or 

 are surrounded by them. Since Cook's voyage, Forster's ob- 

 servations have given occasion to geologists to think that many 

 islands and entire countries have owed their origia to the coral 

 produced by these animalcules. I have seen some of these co- 

 ral islands covered with a pitiful vegetation, and I have no 

 doubt that many of those of the Pacific Ocean have been form- 

 ed in this manner. It appears to me, however, that too much 

 importance has been attributed to this theory, on which M. 

 Adelbert de Chamisso, an excellent observer, has thrown much 

 light. In the West Indies, for example, limestone rocks of ter- 

 tiary formation, which contain petrified madrepores and tubi- 

 pores, have been taken for recent works of coral animals, mere- 

 ly because they occur in places where similar animals are still 

 observed. But when we penetrate into the interior of the large 

 Antilles, there occur mountains of primitive formation, which to 

 a great height are surrounded by the same madrepore rocks. 

 These rocks have, consequently, emerged from the chaos of an 

 ancient world. Between the tropics, on the shores of tlie 

 Gulf of Mexico, the traveller runs the risk of confounding with 



