This is especially the case in the higher Heteroptera, where the cephalic ganglion or brain is massive, closely connected with the subcesophagial ganglion by two stout cords which pass below the gullet, and this in turn is immediately followed by the great thoracic ganglia, all three of these being fused together and continued some distance backward by a great nervous trunk.

The brain often consists of a pair of distinct lobes, from which two heavy branches pass off to the eyes, more slender ones to the antenna-, and one to each of the two or three ocelli.

From the ganglion beneath the gullet the mouth-organs are supplied with branches, and from the thoracic ganglia and terminating trunk great branches run off and ramify upon all the organs within the cavity of the body.

The muscles of the Hemiptera are generally powerful and numerous, and are ar- ranged chiefly with special reference to the movement of large organs of the body, such as the legs, wings, and head.

Accordingly they are centred most in large bun- dles, in the three great chambers of the thorax, and almost fill the cavity of the prothorax.