139 

 Snails and Slugs. 



These animals are so familiar that they will be recognized 

 without description. The slugs are in form and anatomy and 

 habits of life about the same as the snails, except that they have 

 no shell. The shell of tlie snail of course offers it protection 

 against outside attacks, and gives it a place in which to with- 

 draw when the air is dry. But snails and slugs require a certain 

 amount of moisture in their surroundings that they may move 

 about, and feed and lay their eggs. The pond snails of course 

 live in the water. The large orange or yellow colored slug to be 

 found in some parts of California is a giant among slugs. 



Land snails and slugs may be easily kept among the plants 

 in a moist space, or under a glass vessel, or in a fernery. They 

 live on vegetable food. The pond snails live well in the aquaria. 

 The parts that maybe studied are: Their method of locomotion, 

 their feeding, their breathing, their eye and touch tentacles, their 

 general habits of life. The eggs are very interesting objects. 

 Even under a low power what can be seen of the gradual change 

 from a small round single cell, to the form of an adult snail or 

 slug is very interesting. Pond snails will often lay a bunch of 

 eggs against the side of the aquarium in a good place for obser- 

 ving the development with a lens. In the spring and summer 

 large numbers of these eggs may be found on the weeds in ditches 

 and ponds. 



Land snails and slugs lay their eggs in moist places such as 

 under stones, pieces of wood, leaves or in moss. They may be 

 obtained if the animals are kept in confinement under the proper 

 conditions at the right season. 



