528 



Phylum Mollusca 



culture are woodland snails, or sod if they are of a type that inhabits 

 open country. Many species are tolerant of either type of environment. 

 Since some woodland species need only a sufficient amount of shade, a 

 grassy substratum is satisfactory in the laboratory where shade and 

 protection from drying are present. As a rule, however, it is best to 

 reproduce the ecological conditions under which the snails originally 

 lived. The soil should be kept alkaline with a sufficient amount of lime; 

 otherwise the culture will be a failure. Fragments of dead shells may 

 be provided for the purpose. The soil should be covered with fresh 

 leaf mold from the woods; if sod is used, it is necessary to keep it in 

 good condition. Two types of shelter should be furnished in addition 

 to what the substratum affords. A few stones, preferably calcareous 

 in composition, should be laid on the bottom of the vivarium. Since 

 many species also seek shelter under rotten logs, a few pieces of rotten 

 wood should be put in the cage. Moss is a very useful addition to the 

 surface of the substratum, for it holds moisture, furnishes shelter to 

 small species or young snails, and is a good place for the laying of eggs. 



Another type of vivarium that gives good results is a flower pot in 

 which a few ferns are planted. This arrangement is excellent for some 

 forest-inhabiting species. It is of course necessary to build up a wall 

 of screening on the sides of the pot to keep the snails from escaping. 

 In this case no roofing is desirable or necessary, since the snails will not 

 crawl up and over the rough surface of the screening. This type of 

 cage possesses the disadvantage of furnishing only a small area in which 

 the snails may move about, but it has the advantage that the soil has a 

 chance to drain and therefore need not be changed for a long time. 

 Eventually, of course, the soil will become leached and the culture is 

 likely to die for that reason. 



The food question is surprisingly simple. Fresh leaf mold furnishes 

 the ordinary food for the forest snails. This diet may be supplemented 

 by lettuce or bran. If the leaves of the tree-of-heaven (Ailanthus 

 glandulosa) are available, they will furnish excellent food, for most 

 snails seem to be inordinately fond of them. Burdock leaves are also 

 very acceptable. 



Moisture must be supplied, for the rooms of most buildings have a 

 very low humidity. Water should be sprinkled lightly over the soil to 

 wet the surface. This may be done daily if necessary. It is easy to 

 decide by inspection whether the culture is getting too dry. It is highly 

 important not to soak the soil. Snails from the drier areas of North 

 America should be kept in cultures that are very seldom wet, for they 

 die in cultures that are sufficiently wet to keep our eastern forms active. 

 It is well to discontinue frequent wetting at times during the inactive 

 period in order to let the snails "dig in" for a few days at a time. 



