MYSTERIOUS MIGRATION 229 



gleam of the moon. Far away the pulsations and shouts from 

 the belated wedding still throbbed in the night air but these 

 sounds were no longer of any importance. Instead the roar and 

 sigh of the gently rising surf occupied my half -conscious hear- 

 ing. The air was warm and heavy with perfume; the trade 

 winds had slackened to an unusual calm. For the first time that 

 evening I felt soothed and dropped on the smooth sand where 

 I drifted into a heavy sleep. 



On and on I dozed and did not stir for nearly an hour. But 

 then into my half conscious senses there crept a multitude of 

 little sounds that I had not heard before— faint scratchings and 

 clatterings, queer little noises barely audible above the surf. 

 Once a mockingbird in the bay lavender back of the beach 

 broke into liquid melody, trilled half-heartedly, and then 

 lapsed into silence. But the scratchings continued. 



Presently they became more frequent, more pronounced. 

 I raised my head. Up on the white beach, gleaming silver in 

 the moonlight, were moving small shadowy forms. In long 

 windrows they were gliding out of the dark bushes and 

 creeping down to the surf. Faintly I could see the glisten of 

 the salt water as it reached their bodies and drenched them 

 with its coolness. For a second their forms showed half smoth- 

 ered in foam and then they disappeared. It was their clattering 

 over the seashells that had awakened me. 



Some moments passed before I realized the full significance 

 of what I was watching. The shadowy forms were crabs— not 

 the checkered Grapsus crabs of the surf nor the crustaceans 

 of the dark blue water, nor yet the ghost crabs that flitted like 

 shadows along the sand just back of the beach, but land crabs- 

 queer round-bodied creatures that lived in holes far back in 

 the interior. They did not belong on the seashore, but had 

 their being in those dry portions of the island where big cacti 

 reared their heads above the soil. There were two kinds of 



