MOEPHOLOGT OF THE BRAIX IX' THE :\IAM.MAI,IA. 385 



" liippocanipus minor," as a supposed distinctive feaiure of the human brain, led to 

 a very heated controversy in ISGl, during- the course of which many anatomists 

 subjected the "occipital " region of the brain in the Primates to a careful examination. 

 One of the most vahiabie results of this unseemly strife avhs the introduction of the 

 useful term " calcarine suhms," which Huxley conferred upon tlu; external furrow, 

 the obverse of which forms the calear avis in the lateral ventricle. Another result 

 was the deuionstratiou by Iluxley, Flower, and others, that the calear and its sulcus are 

 not distinctive of the human braiu, but are commoQ to all the Apes or even Primates, 

 according- to Flower*. 



The calear was first described early in the eighteenth century by Morand f, who 

 likened the little projection on the mesial wall of the posterior eoruu of the lateral 

 ventricle (in the human brain) to a cock's spur and ctiUed it ''ergot,'' the Latin 

 equivalent of which is '' calear acis." Towards the latter part of the same century 

 Vicq-d'Azyr J called it " //ippocamjxiis minor," because it appeared to be continuous with 

 the larg-er swelling known as hippocampus \^major'\. 



According- to Broca, Cruveilhier § was probably the first writer to detinitely refer to 

 the constancy of the sulcus which produces the calear, or " aufractiiosite de la caritc 

 dUjilalc " as he called it. 



In 185 i Gratiolet wroug-ly believed || that the sulcus in question was continued into 

 the hippocam2)al fissure, and included both under the latter name. This misconception 

 heljoed to estal)lish the misleading name " hippocampus minor " which Vicq-d'Azyr had 

 introduced. The merit belongs to Huxley of pointing out the fallacy of Avhich these 

 names were the expression, and, by reinstating the name calear avis and introducing the 

 new term " calcarine sulcus,'' he rid Descriptive Anatomy of a serious source of confusion. 

 I have introduced these historical notes here, because it has unfortunately become 

 necessary to emphasize once more, firstly, the contention of Huxley that the term 

 " hippocampus minor " should be for ever banished with the misconception which it 

 symbolizes; and that the term "calear avis," or simply "calear," be substituted; and, 

 secondly, that the true and exact significance of the term "sulcus calcarinus" may not 

 be forgotten, as it is by most modern writers oia the anatomy of the brain. As the name 

 " calcarine" is derived from "calear," it necessarily follows, as Huxley showed, that the 

 essential part of the sulcus and tliat strictly deserolag the title " calcarine" is thefun'ow 

 which produces the calear avis. But Huxley himself pointed oiit that the sulcus " extends 

 beyond the calear and the jwsterior cornu"^f. And he also did much more than this. 

 For, profiting by the earlier and not wlioUy successful attempt of Gratiolet, he for the 

 first time clearly distinguished among the complex arrangement of mesial sulci the 

 distinct hipiiocampal, calcarine, collateral, and parieto-occipital elements. Huxley 



* '■ Oh the Posterior Lobes of the Cerebrum of the Qiiadrumanu," Phil. Traus. ISG2, pp. 185 et seq. 



t Morand, ' Hi.stoire de TAcademie,' 1744. 



t Vieq-d'Azyr, ' Traite d'Aiiatomic et de I'hysiologie," tome i. J 7S6. 



§ Cruveilliier, ' .\natomie Descriptive,' l'"^'"" Edition, 1H.i6, torn. iv. p. <>()3. 



|l Modern neurological literature eoiitains iiiuiuueralde repetitions of this error. 



% "The Jjrain oF Atcltx,'' Troe. Zool. Hoc. !S!Jl, p. 2oo. 



56* 



