What is the =general shape= of its body? (Fig. 106.) Where is the body thickest? Is it bilaterally symmetrical, that is, are the two sides of the body alike? Is the _skeleton_, or hard part of the body, internal or external? Is the skeleton as stiff and thick as that of a crawfish? What is the length of your specimen? Its color? Why does it have this coloration? In what ways does the grasshopper resemble the crawfish? Differ from it? [Illustration: FIG. 106.--A GRASSHOPPER.] =The Three Regions of the Body.=--The body of the grasshopper is divided into three regions,--the _head_, _thorax_, and _abdomen_. Which of these three divisions has no distinct subdivisions? The body of the grasshopper, like that of the earthworm, is made of _ringlike segments_. Are the segments most distinct in the head, thorax, or abdomen? Which region is longest? Shortest? Strongest? Why? Which region bears the chief sense organs? The appendages for taking food? The locomotory appendages? Which division of the body is most active in breathing? =The Abdomen.=--About how many segments or rings in the abdomen? Do all grasshoppers have the same number of rings? (Answer for different species and different individuals of the same species.) The first segment and the last two are incomplete rings. Does the flexibility of the abdomen reside in the rings, or the joints between the rings? Is there merely a thin, soft line between the rings, or is there a fold of the covering? Does one ring slip into the ring before it or behind it when the abdomen is bent? As the grasshopper =breathes=, does each ring enlarge and diminish in size? Each _ring is divided into two parts_ by folds. Does the upper half-ring overlap the lower half-ring, or the reverse? With magnifying glass, find a small slit, called a _spiracle_, or breathing hole, on each side of each ring just above the side groove (Fig. 106). A tube leads from each spiracle. While the air is being taken in, do the two portions of the rings move farther apart? When they are brought together again, what must be the effect? In pumping the air, the abdomen may be said to work like a bellows. Bellows usually have folds to allow motion. Is the comparison correct? How many times in a minute does the grasshopper take in air? If it is made to hop vigorously around the room and the breathing is again timed, is there any change? [Illustration: FIG. 107.--A GRASSHOPPER DISSECTED.] Find the =ears= on the front wall of the _first abdominal ring_ (Fig. 107). They may be seen by slightly pressing the abdomen so as to widen the chink between it and the thorax. The ears are merely glistening, transparent _membranes_, oval in form. A _nerve_ leads from the inner surface of each membrane. State any advantage or disadvantage in having the ears located where they are.