THE STORY OF THE LAND SNAILS 349 



but very rarely occur, but time is long and snails 

 are patient, and what might not happen to-day or 

 this year or this century might take place a good 

 many times in ten or twenty thousand years. 

 There are certain keys in Lower Florida where all 

 the conditions seem perfectly fit for Liguus, but 

 the most careful search does not discover any 

 trace or sign of them; it is probable that these 

 snails were never landed on their shores in such 

 manner that they could become established. 



Having once become colonized on the keys or 

 in some hammock near the shore on the mainland 

 it is of interest to know how the snails pass from 

 one island to another or from hammock to ham- 

 mock. Mr. Charles Mosier, who has lived for 

 several years on Paradise Key in the Everglades 

 and who has had exceptional opportunities for 

 studying the Liguus, tells me that he has seen 

 crows carrying them in their beaks during flight 

 with intention no doubt of eating them. One 

 of these with eggs dropped on an island or in a 

 hammock would most likely start a new colony. 

 Hurricanes might also account for much local 

 dispersal. 



The arboreal snails live in the hammocks be- 



