162 CRUISE OF THE BARRERA 



rock farther removed from the beach is not sub- 

 jected. It is to this salt spray action that the 

 peculiar quality and the extraordinary carving 

 into sharp knife-blade projections are undoubtedly 

 due, but just why this combination of salt spray 

 with alternate drying and wetting, rain-water, and 

 sun, should produce this remarkable result I can- 

 not even hazard a guess. 



The appearance of the rock, all of reef origin, 

 that begins just back of the shore strip and forms 

 the floor of the entire peninsula is also exceedingly 

 rough. It is full of holes great and small, the mass 

 being tunneled and eroded into a jumble inde- 

 scribably complicated, but the results of weathering 

 show rounded edges and never the knife-blade 

 effect. It is also somewhat less homogeneous 

 and shows in some places its coral structure. 

 As practically all the interior of the peninsula 

 ending in Cape San Antonio is forested, the ex- 

 posed rock of the forest floor is subjected to a 

 special form of erosion which may explain its own 

 peculiar appearance. Every little hole and cre- 

 vice on the surface receives a deposit of humus, 

 twigs, and leaf mould which, soaked in rain-water, 

 distills some organic acids which act upon the 



