MacCaughey] THE TREE SHELLS OF HAWAII 335 



of these shells, cleaned and arranged, is a decidedly attractive 

 natural history exhibit. 



The Hawaiians have an interesting superstition to the effect that 

 the little tree-snails can sing. At night in the forest the chirruping 

 of the crickets is very noticeable. This was probably confused 

 with the snails by the simple-minded natives. Certainly no white 

 man has ever heard a tree-snail sing ! Although the Hawaiians are 

 very fond of various kinds of sea snails, they did not use the tree- 

 snails for focd; at least, such use was rare. Occasionally they 

 would string the bright shells in necklaces or garlands. 



Some of the snails lay eggs; other kinds give birth to fully 

 hatched young. The food of the snails is more or less of a mystery. 

 They glide along the surfaces of the leaves, but apparently do not 

 remove any of the substance. It has been suggested that they feed 

 upon the delicate fungus material which grows upon the leaves, 

 and which is almost invisible. At any rate they do not eat holes 

 in the leaves, as do ordinary garden snails and slugs. 



Not only are the Hawaiian tree-dwelling snails found nowhere 

 else in the world, but their geographic ranges in the islands are 

 very limited. Many kinds can be found only in certain very small 

 localities, a few square rods or acres in area. Those kinds which 

 inhabit a certain ridge or slope may be entirely different from those 

 upon another ridge only a fraction of a mile away. Each valley- 

 side has its own kinds of snails. Shells that were fairly abundant 

 fifty years ago are now upon the verge of extinction. This is due 

 to zealous collectors, as well as to the destruction of the forests by 

 man, wild goats, insect pests, and other agencies. Anything that 

 injures the forest injures all the native life within the forest ; thus 

 many of the Hawaiian tree-snails and also beautiful birds have 

 become excessively rare. 



Nearly every American boy in Hawaii at some time or other has 

 made a collection of tree-snails, or "land shells" as they are called 

 locally. Many scientists from Europe and America have devoted 

 much laborious research to this remarkable group of molluscs. 

 In Honolulu are a number of very large and complete collections of 

 the tree shells, — collections that represent the labors of many 

 decades, and that are of great scientific value. To open one of 

 these cabinets is like uncovering an exhibit of precious stones. 

 The successful "shell collector" must have sharp eyes, strong legs, 

 and plenty of patience. The snails are motionless among the 

 dense foliage and are easily overlooked An amateur will gather 



