Exposing the brain, and other structures.

1. Cut along the dotted line of Plate 1C, using the point of the knife.

The isolated portion of the wall will come away easily. Conspicuous on the summit of the brain are the purple retinae of the three ocelli.

2. Extend the opening to each side, cutting away part of the compound eyes (Plate 8A).

Both knife and scissors can be used for this part of the work.

3. In a freshly killed bee, clear away the large tracheal sac filled with air, which obscures the brain.

4. Observe:

   4.1. the protocerebrum, bearing the ocelli;

   4.2. the optic lobes connected with the compound eyes.

   The pigmented parts of the compound eyes indicate the radiating ommatidia;

   4.3. the hypopharyngeal glands in front of the brain.

   They are conspicuous in young nurse bees and winter bees, in which the acini are large and white, but in foragers
   they are much shrunken and may be difficult to find;

   4.4. another branch of the hypopharyngeals;

   4.5. a small part of the postcerebral glands behind the brain.