=Ovipositor.=--If the specimen is a female, it has an egg-placer or
ovipositor, consisting of _four blunt projections_ at the end of the
abdomen (Fig. 107). If it is a male, there are only two appendages.
These are above the end of the abdomen, and smaller than the parts of
the ovipositor. Females are larger and more abundant than males. In
laying the eggs, the four blunt points are brought tightly together and
then forced into the ground and opened (Fig. 108). By repeating this, a
pit is made almost as deep as the abdomen is long. What sex is shown in
Fig. 106? Fig. 107?
=Draw= a side view of the grasshopper.
[Illustration: FIG. 108.--GRASSHOPPER LAYING EGGS. (Riley.)]
=Thorax.=--This, the middle portion of the body, consists of _three
segments_ or rings (Fig. 107). Is the division between the rings most
apparent above or below? Which two of the three rings are more closely
united?
The front ring (_prothorax_) of the thorax has no rings. Is it larger
above or below? Does it look more like a collar or a cape? (Fig. 106.)
A spiracle is found on the second ring (_mesothorax_, or middle thorax)
just above the second pair of legs. There is another in the soft skin
between the prothorax and mesothorax just under the large cape or
collar. The last ring of the thorax is called the _metathorax_ (rear
thorax).
How many =legs= are attached to each ring of the thorax? Can a
grasshopper walk? Run? Climb? Jump? Fly? Do any of the legs set
forward? (See Fig. 106.) Outward? Backward? Can you give reasons for
the position of each pair? (Suggestion: What is the use of each pair?)
If an organ is modified so that it is suited to serve some particular
purpose or function, it is said to be _specialized_. Are any of the
legs specialized so that they serve for a different purpose than the
other legs?
The leg of a grasshopper (as of all insects) is said to have _five
parts_, all the small parts after the first four parts being counted
as one part and called the foot. Are all the legs similar, that is, do
the short and long joints in all come in the same order? Numbered in
order from the body, which joint of the leg is the largest,--the first,
second, third, or fourth? Which joint is the shortest? The slenderest?
Which joint has a number of sharp points or spines on it? Find by
experiment whether these spines are of use in walking (Fig. 106).
Jumping? Climbing? In what order are the legs used in walking? How many
legs support the body at each step?
[Illustration: FIG. 109.--HOW A GRASSHOPPER WALKS.]
[Illustration: FIG. 110.--HOW A SPIDER WALKS.]
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