A GRASSHOPPER 11 
In the male the ninth and tenth sternites are present, although 
they may be fused so as to appear as one plate. An additional 
ventral plate, called the genital plate, forms the posterior extremity 
of’the body. The tenth tergite is very small; the podical plates 
and the cerci are large. Beneath the eleventh tergite is the 
anus. Compare a male with a female abdomen and identify the 
parts above mentioned. 
On the lateral side of the first abdominal segment note the 
auditory organ, a large circular opening covered by a membrane. 
With the aid of a hand lens find the spiracles of the thorax and 
the abdomen. Ten pairs are present, one pair on the anterior 
margin of both the meso- and the metathoracic segments, and 
one pair on each of the eight anterior abdominal segments, that 
on the first abdominal segment being just within the margin of 
the auditory organ. 
Exercise 1. Spread out and pin down all four wings and draw 
an outline of the dorsal aspect of the grasshopper on a 
scale of 2 to 4. Number the thoracic and the abdominal 
segments, and label all the parts observed. 
Exercise 2. Cut off the wings from the left side of the body 
and draw an outline of the side view of the thorax and the 
two anterior abdominal segments on a scale of 5 or 6. 
Note that both the meso- and the metapleurum are divided 
by a diagonal suture into two portions. Number the seg- 
ments and label all the parts. 
Exercise 3. Draw a side view of the posterior end of your 
specimen (whether male or female) on a scale of 5 or 6, 
showing accurately the arrangement of all the parts, and 
label them all. 
Exercise 4. Draw an outline of the ventral surface of the 
thorax on a scale of 5 or 6. Note the dovetailing of the 
anterior margin of the metasternum with the posterior 
