. Anatomy, descriptive and applied. Anatomy. 926 THE NER VE SYSTEM four, or five shorter preinsular gyres {gyri breves insulae), built upon a radiate plan, converging in the region of the insular pole. As already hinted, the island of Reil represents an area of the brain mantle whose growth did not keep pace with that of the surrounding parts; hence its submergence by them. The close appo- sition of the insular region to the subjacent basal ganglia, and the failure of devel- opment of great masses of projection fibres so prominent elsewhere, were doubt- lessly factors therein. The insular cort
. Anatomy, descriptive and applied. Anatomy. 926 THE NER VE SYSTEM four, or five shorter preinsular gyres {gyri breves insulae), built upon a radiate plan, converging in the region of the insular pole. As already hinted, the island of Reil represents an area of the brain mantle whose growth did not keep pace with that of the surrounding parts; hence its submergence by them. The close appo- sition of the insular region to the subjacent basal ganglia, and the failure of devel- opment of great masses of projection fibres so prominent elsewhere, were doubt- lessly factors therein. The insular cortex is uninterruptedly continuous with the rest of the cortex, but it has become specialized into the purest association centre in the cerebrum, and we shall learn of its intimate relations to the faculty of speech on page L supposedly transparent cerebral hemisphere, w by the opercLila. The Rhinencephalon, or Olfactory Lobe {lobus olfactorius) (Figs. 684, 685).— The grouping of the parts constituting the central olfactory structures under the term "rhinencephalon" as distinguished from the rest of the fore-brain (pallium) was first clearly made by Turner and proved by His to be embryologically well founded and by Edinger to agree with phylogenetic development. More light has been thrown upon the subject recently by Retzius and Elliott Smith. The sense of smell, while highly useful in the quest for food in earlier and lower forms of vertebrates, is relatively litde used in the mental life of man. The enormous preponderance of the cerebral mantle and the concomitant atrophy of the rhinen- cephalon in the human brain afford one of the most striking contrasts in brain morphology. This relatively feeble development in bulk of the olfactory apparatus in the human brain by no means renders its description simple. In fact, not until its development in lower macrosmatic animals was studied could anatomists form even an approximately clear conception of the seemingly di
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1913
