NATURAL SUBDIVISION OF THE CEEEBEAL HEMISPHERE. 449 



the " pallium." I began using the latter term in this peculiar 

 sense as the result of a misreading of Turner's memoir of 1890. 

 Equipped with only that superficial knowledge of the nervous 

 system which the average medical student possesses, I commenced 

 the study of what is perhaps the most generalised and ideally 

 simple brain — that of Ferameles — in the whole Mammalian 

 series. Under such circumstances it was only natural to recog- 

 nise in the area called here the " neopallium " a region emi- 

 nently worthy of separate and distinctive recognition ; and I, 

 unconsciously, " read into " Turner's memoir my own views on 

 morphology, which are the same now in regard to this matter 

 as they were then.^ So that when he spoke of the rhinal and 

 hvppocampal fissures as being the limits of the " pallium," I 

 somewhat hastily concluded that he did 7iot include the hippo- 

 campus in his " pallium " — a view for which, of course, there is 

 no warrant in his memoir. But although I have thus for more 

 than six years been using the term " pallium " in a sense whicli 

 is different from that of other writers, and altogether foreign to 

 the idea of Reichert, I must in justice point out that such a 

 usage implies an important morphological fact not hitherto 

 duly recognised. At the same time, I took a liberty with the 

 term " pallium " which is no greater than that of Turner and 

 His in their employment of the same expression. 



It must be obvious, from the preceding discussion, that the 

 terms " rhinencephalon " and " pallium " cannot be employed as 

 complements the one of the other without considerable distor- 

 tion of the original meaning of one or both of the terms. 



The pallium, in the strict sense, is composed of three distinct 

 structural elements : a ventral part, or pyriform lobe, the " basi- 

 2MUi'um,"^ the marginal pallium or hippocampus, and lastly 

 that large dorsal cap the " dorsiiJallium " or neopallium. If 

 now we regard this term " neopallium " as the complement of 

 " rhinencephalon," it will involve a new definition of the latter, 

 which would then include the whole pyriform lobe, the whole 

 hippocampal formation and paraterminal body, in addition to 



^ Proc. Linn. Soc. New South Wales, vol. ix. (2nd ser. ), part 4, 1894, 

 p. 648. 



^ G. Retzius [" Zur iiusseren Morphologic des Riechhirns," Biologisch, Unter- 

 such., Bd. viii., No. 2, 1898, p. 25] emploj's this term in an analogims Uut 

 somewhat diti'erent sense. 



