THE GRASSHOPPER AND THE SNAIL 7 



small particles of the leaf are rasped off. Leaves which have 

 been fed on will show the rasped or scraped places. 



Find also, usually just at the surface of the water, when 

 the snail has come up to breathe, a small hole on the right 

 side of the body; this is the breathing pore, and air entering 

 here passes into a small sac-like space, a simple kind of 

 lung. 



Examine a shell and note the following parts: the aperture 

 at the large end, the apex or pointed end, the lip or outer 

 edge of the aperture, the lines of growth parallel with the lip, 

 the suture or spiral groove on the outside, the spire compris- 

 ing all the whorls or turns, and the columella or inner axis 

 of the spire. Do the whorls of all the shells turn the same 

 way? What is the use of the shell? 



Make a drawing of the right-hand side of a snail and its 

 shell representing the animal fully extended; name all the 

 parts of the snail and shell. 



If pond snails cannot be found, garden snails or slugs 

 may be studied. The slug is a snail-like animal without 

 a shell. 



