The thorax

1. Remove the left side of the thorax.

2. Excavate, removing the flight muscles and lowering the walls as the work proceeds.

3. Observe:

   3.1. the attachment of the vertical muscles to the floor and roof of the thorax;

   3.2. the attachment of the longitudinal muscles to the roof and first phragma in front, and to the second phragma in
   the rear;

   3.3. the aorta, which can be found when approaching the mid-line of the thorax, between the right and left sets of
   longitudinal muscles, and below it

   3.4. the oesophagus;

   3.5. the ganglia;

   3.6. the commissures;

   .7. the anterior end of the ventral diaphragm, which enters the thorax through the petiole.

4. Remove everything else.

5. Observe:

   5.1. the direct wing muscles on the inner surface of the right hand wall of the thorax.

A special preparation to show the direct muscles can easily be made by slicing off one side of a thorax with a razor blade and trimming away debris.