THE STORY OF THE LAND SNAILS 347 



had been swept down a much swollen stream into 

 the bay. Their stems were standing almost erect, 

 and they could have easily carried for thousands 

 of miles a cargo of living snails at a safe height of 

 five to twenty feet above the sea. 



It is easy to believe that decaying logs in tropi- 

 cal forests might be a means of dispersing mol- 

 lusks. Some of the ground snails live on such 

 logs, and arboreal species as already stated lay 

 their eggs in their crumbling surfaces. These 

 logs are washed out in time of violent rains and 

 carried out to sea like the bamboos. Living trees 

 too with snails attached are torn out and swept 

 seaward by the same means. From Cape Saint 

 Roque to well up in the Caribbean the sea in many 

 places is eating constantly into the alluvial shore 

 and undermining thousands of acres of virgin for- 

 est. I have seen such timber being so undermined 

 along the Honduras coast. Every hard storm 

 would loosen a number of these and set them 

 adrift. Through a long voyage some limbs might 

 remain entirely out of water or only be occasionally 

 immersed. Darwin states that he placed several 

 species of land snails in sea water for seven days 

 and that they suffered no injury whatever. On one 



