on the Surface of the Morea. ^ 



When the opening is in the middle of the plain as at Kava- 

 ros (Pyrrichus), in the peninsula of Tenarus and at Tripolitza, 

 its existence in summer is detected only by a deposit of reddish 

 mud, split in all directions; but when situated in rocks at the 

 bottom of mountains, it is often so spacious, that in summer 

 one can penetrate into the interior. Examples of this kind are 

 to be found in the gulfs of lakes Stymphalus, and Copais ; and 

 that of Tipiana near Mantinea, in the interior of which, a mill 

 has been erected to take advantage of the fall of water. On 

 entering it, we discover chambers with smooth walls, narrow 

 passages and lakes, as in the caverns which have so frequently 

 been described. 



The existence of these clefts, which is the cause of the dry- 

 ing up of the enclosed basins, evidently arises from the hardness 

 and extreme fragility of the compact limestone, which, at the 

 time of the dislocation of the strata, has been broken to pieces, 

 without either heaping up or sinking, and has left numerous 

 chasms and loose debris. 



A circumstance, however, which is favourable to the passage 

 of water and the formation of caverns of " deblaiement,"" rather 

 than of erosion, is the presence, below the calcareous matter, 

 of a great arenaceous series (greensand) which the waters carry 

 off with facility ; consequently, cavities have increased, and have 

 been also liable to be closed up on the instant, when the sup- 

 ports give way. 



As the majority of these gulfs are unable to afford a passag-e 

 for all the water during the rainy season, lakes are formed 

 around their openings. The ground is raised up by depo- 

 sits of alluvion, and the torrents are unable to carry along with 

 them any thing else except sand, mud, and vegetable and animal 

 debris, which are capable of floating. In short, the elevation of 

 the alluvium becomes such, that the torrent throws itself out in 

 another part of the plain, where it cannot fail to find new open- 

 ing!? ; and it is in this manner, that, flowing successively through 

 its whole extent, it is maintained at a level which is nearly uni- 

 form ; such at present is the nature of all the torrents in the 

 plain of Tripohtza. Of course the deposits in the caverns and 

 internal lakes must consist of red earth, sand, bones, and vege- 

 tables, like the greater number of the bone caverns. 



In summer, the lakes become more or less completely dry, 



