202 THE NA TURE-STUD Y RE VIE IV [2 . 6 -sept., .906 



which the spiral is turned. At this point make a drawing of a snail 

 in winter quarters. Place the shell with apex up and the mouth to- 

 ward you and in this position all the important structure can be 

 brought into one sketch. 



At the close of the above lesson, have ready tumblers containing a 

 half inch of fine gravel or sand and enough water to keep the gravel 

 wet. Into each of these place a snail and -then cover, leaving just a 

 little air space. The children are to keep these dishes under obser- 

 vation until the snails become active. Then begin the next lesson bv 

 having the children tell just what the snail looked like in winter 

 quarters, what they did with them and what has happened to the 

 snail since their last lesson. Just what was necessary to loosen the 

 plaster plate ? (In their natural homes the snail goes into winter 

 quarters in autumn when the soil becomes cold or dry, and when 

 spring returns with its warmth and moisture the little plaster plate 

 drops out just as it did in the schoolroom and the animal begins to 

 hunt for something to eat. The door forms an efficient protection 

 against dryness and insects or other enemies. Snails have been 

 known to remain in their dormant condition for upwards of six years.) 



Take a dormant snail, pry off the plaster plate with a knife. One 

 or more transparent films (curtains) may then be seen. After re- 

 moving these, notice how the animal is tucked away in its shell. 

 Usually only the yellow collar, to be described later, is seen; and a 

 large hole (for breathing) is visible on the right side. If these 

 structures are not seen clearly at this point there will be plenty of 

 opportunity to see them later when some active animal withdraws 

 within its shell to rest. 



II. Study of the Snail in its Active Condition 



Each child (or, if necessary, groups of three or four) should have 

 a piece of glass at least 4x5 inches. Old photographic negatives may 

 be cleaned with hot water and washing soda. Place the snail on a 

 glass plate and it will soon begin to crawl. 



Place a bit of lettuce before the snail and do not touch or jar the 

 animal. If not disturbed, it will crawl to the lettuce and begin to 

 feed, being very hungry, not having had food since last summer. 



Notice on the end of the head are two pairs of soft, flexible organs 

 (feelers). The upper and larger ones bear at their ends each a tiny 

 black dot (eye). Do you see eyes on the shorter, lower feelers? 



