[Illustration: Fig. 45.--A, lobes of the brain of the Cockroach, seen from within; _c_, cauliculus; _p_, peduncle; _t_, trabecula. B, ditto, from the front; _ocx_, outer calyx; _icx_, inner calyx. C, ditto, from above. Copied from E. T. Newton.] This central framework is invested by cortical ganglionic cells, which possess distinct nuclei and nucleoli. A special cellular mass forms a cap to each pair of calices, and this consists of smaller cells without nucleoli. Above the meeting-place of the trabeculæ is a peculiar laminated mass, the _central body_, which consists of a network of fibres continuous with the neighbouring ganglionic cells, and enclosing a granular substance. The antennary lobes consist of a network of fine fibres enclosing ganglion cells, and surrounded by a layer of the same. It is remarkable that no fibrous communications can be made out between the calices and the cauliculi, or between the trabeculæ and the œsophageal connectives. [Illustration: Fig. 46.--Model of Cockroach Brain, constructed from slices of wood representing successive sections.] [Illustration: Fig. 47.--Right half of Model-brain seen from the inner side, with the parts dissected away, so as to show the anterior nervous mass (_cauliculus_), _a_; the median mass (_trabecula_), _m_; the mushroom-bodies (_calices_), _mb_; and their stems (_peduncles_), _st_. The cellular cap, _c_, has been raised, so as to display the parts below: _com_, is a part of the connective uniting the brain and infra-œsophageal ganglia. [Figs. 45–48 are taken from Mr. E. T. Newton’s paper in “Journ. Quekett Club,” 1879.]] [Illustration: Fig. 48.--Diagrammatic outlines of sections of the Brain of a Cockroach. Only one side of the brain is here represented. The numbers indicate the position in the series of thirty-four sections into which this brain was cut. _al_, antennary lobe; _mb_, mushroom bodies (_calices_), with their cellular covering, _c_, and their stems (_peduncles_), _st_; _a_, anterior nervous mass (_cauliculus_); _m_, median nervous mass (_trabecula_). From E. T. Newton.] [Illustration: Fig. 49.--Frontal section of Brain of Cockroach. _C_, cellular layer beneath neurilemma; _ICx_, inner calix; _OCx_, outer calix; _GC_, ganglion-cells; _P_, peduncle; _T_, trabecula; _Op_, optic nerve; _AnL_, antennary lobe. × 24.] _Sense Organs. The Eye of Insects._