. A dictionary of birds . rkinjeslayer), and exter-nally covered by agrey mantle ofsmaller ganglioniccells. Such a thinsection, especiallywhen stained withcarmine, forms afascinating objectfor the microscope,and is easily surface ofthe cerebral hemi-spheres in Birdsexhibits no convol-utions or gyrationsas in the higherMammals. In theRatitaj and in manyPasseres the surfaceis entirely smooth,but in Swimmers,Waders, Pigeons,Fowls, and Birds-of-Prey, there is avery slight furrowwhich might becompared with the Sylvian fissure. There is also very little greysubstance in the surface layers o
. A dictionary of birds . rkinjeslayer), and exter-nally covered by agrey mantle ofsmaller ganglioniccells. Such a thinsection, especiallywhen stained withcarmine, forms afascinating objectfor the microscope,and is easily surface ofthe cerebral hemi-spheres in Birdsexhibits no convol-utions or gyrationsas in the higherMammals. In theRatitaj and in manyPasseres the surfaceis entirely smooth,but in Swimmers,Waders, Pigeons,Fowls, and Birds-of-Prey, there is avery slight furrowwhich might becompared with the Sylvian fissure. There is also very little greysubstance in the surface layers of the hemispheres. Various attemptshave been made, by Tiedemann,^ Serres,^ Leuret,^ and Bumm,* tocompare the weight of the whole brain with that of the body, or 1 Anatomie und NaturgescMchte der Vogel. Heidelberg : 1810.^ Anatomie comparee du cerveau. Paris : 1824.^ Anatomie comparee du systbne nervcux. Paris : 1839-57.* Das Grossliirn der Vogel. Zeitschr. fiir wisscnsch. Zool. xxxviii. (1883)pp. 430-4C6, tabb. Ventral view of the brain of a Goose. Twice natural size.(After A. Meckel.)I-XII, thje twelve pairs of cranial nerves; Ch. Cliiasma of theoptic nerves cut across; Fl. Flocculus; H. Hypophysis; lobe; Lq. Laqueus; Sylvian fissure; First spinalnerve. 54 BRAIN the weight of the hemispheres with that of other parts of the cen-tral nervous system, in order to draw conclusions as to the intelli-gence of various Birds. When Birds are arranged according to thepreponderance of the hemispheres over the rest of the brain, the firstplace is taken by the Passeres and Parrots (27 or 20 to 1), thenfollow Geese, Ducks, Waders, and Birds-of-Prey, lastly Fowls andPigeons, the proportions in the Common Domestic Pigeon being095 to 1, the forebrain weighs less than the rest, while in manyOscines it Aveighs nearly three times as much. The attempts tosort Birds according to the proportion of brain to body have ledto no practical results, chiefly because the
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbirds, bookyear1896
