Hardwicke's science-gossip : an illustrated medium of interchange and gossip for students and lovers of nature . ommissuresdo not exist, but that there are numerous transverse fibres con-necting the ganghonic cells of one side with the peripheralnerves of the other (Zeits. f. wiss. Zool., 13d. p. 6q6,1881). homologies of many parts are as yet altogetherobscure. The comparative study of new types willhowever, in time, bridge over the wide intervalbetween the insect-brain and the more familiar verte-brate brain, which is partially illuminated by physio-logical experiment. Mr. E. T. Newto
Hardwicke's science-gossip : an illustrated medium of interchange and gossip for students and lovers of nature . ommissuresdo not exist, but that there are numerous transverse fibres con-necting the ganghonic cells of one side with the peripheralnerves of the other (Zeits. f. wiss. Zool., 13d. p. 6q6,1881). homologies of many parts are as yet altogetherobscure. The comparative study of new types willhowever, in time, bridge over the wide intervalbetween the insect-brain and the more familiar verte-brate brain, which is partially illuminated by physio-logical experiment. Mr. E. T. Newton has publisheda clear and useful description * of the internal andexternal structure of the brain of the cockroach,which incorporates what had previously been ascer-tained with the results of his own has also described f an ingenious method ofcombining a number of successive sections into adissected model of the brain. Having had theadvantage of comparing the model with the originalsections, we offer a short abstract of Mr. Newtonsmemoir as the best introduction to the subject. He <^-T. (con Fig. 147.—A, Lobes of the brain of the Cockroach, seen fromwithin; c, cauliculus;/, peduncle; t, trabecula. B, ditto,from the front ; ocx, outer calyx ; icx, inner calyx. C, ditto,from above. [Copied from E. T. Newton.] describes the central framework of the cockroachbrain as consisting of two solid and largely fibroustrabecular, which lie side by side along the base ofthe brain, becoming smaller at their hinder ends ;they meet in the middle line, but apparently withoutfusion or exchange of their fibres. Each trabecula iscontinued upwards by two fibrous columns, thecauliculus in front, and the peduncle behind ; thelatter carries a pair of cellular disks, the calices (thecauliculus, though closely applied to the calices, isnot connected with them) ; these disks resemble twosoft cakes pressed together above, and bent oneinwards, and the other outwards below. Thepeduncl
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