NATURAL HISTORY OF THE RIVIERA. 231 



smoke, which in the still air floated slowly across the precipice and 

 vanished out at sea. 



Six hundred feet above us, a pair of Alpine swifts were darting 

 to and fro, selecting a convenient place, secure and dry, in which to 

 build their nest. Their white throats were distinctly visible as we 

 stood below, and we wondered if they appreciated the scenery 

 around, or whether it passed unnoticed. We also wondered what 

 they thought of us from their Agapemone up there. Did they envy 

 us, the lords of creation ; or, as they could only see the crowns 

 of our hats, did they rank us as black wingless beetles moving 

 tediously along ? This wonderfully beautiful spot appears almost 

 deserted. We saw no signs of anyone along the road, and on the 

 shore below a solitary angler was fishing from the rocks. Truly, I 

 thought, as I watched this man, your lines are cast in pleasant 

 places ; but probably he also cared far less for the beauty of the 

 place than its ability to supply him with his daily food. 



There are several large caves close by, which were used by men 

 in former days, when house-building was unknown. We climbed 

 up with difficulty into one of them, which was nearly filled by a 

 tremendous rock, fallen from the roof above, and almost hidden 

 by masses of maidenhair ferns. There was another cave a 

 hundred feet above us, inaccessible from below ; but, as there is a 

 great hole admitting daylight through the roof, it could probably be 

 entered with the aid of a rope ladder from above. Those who study 

 man's early history would doubtless find many of his relics there. 

 The only present tenant we could see was a blackstart {Ruticilla 

 tithys), which had left its pure white eggs, to watch us with jealous 

 eyes so long as we remained in sight. 



All along our route the rocks have been laid bare by the workmen 

 who made the road, and the geologist may study the various forma- 

 tions at his leisure. Limestone predominates, and when burnt in 

 furnaces it produces the purest lime known to builders. The water 

 trickling through it has also cemented together vast beds of pebbles, 

 which in ages past formed the shores of primeval seas, kept in 



