Fig. 46.—Model of Cockroach Brain, con­struct­ed from slices of wood rep­re­sent­ing suc­ces­sive sec­tions.

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.]

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.