to observe closely the snail's method of drawing the eye peduncle into 

 the body. After remaining retracted for a few seconds, the peduncle 

 was again stretched out. This time we watched intently as Harry 

 lightly tapped the eye. As it retracted, we saw the black eye run 

 down the interior of the peduncle and disappear in the head. Howard, 

 who was nearest the animal, suddenly exclaimed, " Why, that is exactly 

 the way my sister pulls off the fingers of her kid gloves." The Pro- 

 fessor smilingly remarked that that was exactly the point he wished 

 us to see, for the eye peduncle is retracted in just the same manner 

 as the finger of a kid glove is turned inside out. He told us that 

 a set of muscles is attached to the inside of the peduncle at the tip, 

 and when the eye is touched, the muscles contract and draw the whole 

 peduncle into the head, outside in. 



Just beneath the eye peduncles, we noticed two short, finger-like 

 organs. These were the true tentacles, with which the animal feels about. 

 The back of the animal was covered with many rounded tubercles, and 

 the center of the tail, or posterior part, had a prominent ridge, or keel. 



Harry now picked up the animal by its shell, and we examined 

 the under surface of its long, wide foot. At first, the animal con- 

 tracted a little into its shell, but soon it stretched out again to its 

 fullest extent, and twisted itself about from side to side, raised its 

 head and thrust its eye peduncles about in every direction in a vain 

 endeavor to find some solid support. George inquired what it was that 

 resembled water and seemed to be flowing over the bottom of the 

 snail's foot. Professor Parker replied that it was the contraction and 

 expansion of the muscles on the under surface of the foot which gave 

 this wavy appearance. " The glistening effect," he said, " is caused 

 by the mucus which is constantly flowing from the foot. If we place 

 a snail on a piece of glass, these wave-like movements may be seen 

 to cause the animal to glide over the surface." 



As we were looking at the foot, we noticed a hole of good size 

 which opened and closed at regular intervals, in that part of the animal 

 remaining in the shell. This, Professor Parker said, was the open- 

 ing into the lung which allowed the fresh air to come in and the impure 

 air to escape. He also reminded us that land snails breathe by means 

 of a true lung, which occupies the last whorl of the shell. " This lung," 

 he said, " is composed of a network of blood-vessels, through which 

 the blood flows after it has passed through the body and is filled with 

 carbonic acid gas. The foul air is expelled and the fresh air enters 

 and purifies the blood, which flows to the heart to be again pumped 

 through the body." 



28 



