18.104.22.168. Exposing the flight muscles (Plates 8A and 12)
The roof of the thorax is best taken off with the knife:
1. Insert the extreme point only, as shown in Plate 1.
2. Make a short slit in the body wall by an outward and forward stroke.
3. Continue this along the dotted line in the Plate, all round the domed roof of T2.
4. Make a longitudinal slit along the mid-line.
Usually the roof is very firmly attached to the flight muscles, and must be detached, again with the point of the knife.
5. Keep the blade in a horizontal position, pass its point under the body wall, through the longitudinal slit, and separate the roof from the muscles by small forward movements, gradually working the point further under the body wall. When the first half of the roof is nearly free, steady it with forceps while completing the separation. If this is done carefully, the muscles will be undisturbed and undamaged, and will have the appearance shown in Plate 8.
6. Remove the other half of the roof.
7. Take off the remainder of the roof, along the second dotted line in Plate 1.
This is not attached to the muscles, and will come off easily.
8. If necessary, remove more of the side walls of the thorax, down to the level of the wings.
The indirect flight muscles are now exposed.