MORPHOLOGY OF THE BRAIX IN THE :VIAMMALIA. 397 



he called central, l. c. Puolaiido's] absent in the Bear, consiilers that the central sulcus of 

 Man is represented in the Carnivora by the coronal sulcus *. 



Bnjca regarded the orliital (presylvian) sulcus of Carnivora as the representative of 

 the human sulcus of Rolando f. 



In 1878 Pacsch once more returned to the discussion of this problem, whicli he had 

 lieen considering for more than ten years. After criticising the views of other writers, 

 and more especially Meynert's, he maintains J the same views concerning the homologies 

 of the coronal and suprasylvian sulci which he advanced three years before {op. cit. supra). 



On physiological grounds Munlc regards the crucial sulcus of Carnivores as the 

 liomologue of the central sulcus of Primates, and cites the recent work of Kiikenthal 

 ixnd Ziehen and of Eberstaller in support of this view. This enumeration of the different 

 views which have l)een enunciated by different writers might l)e considerably extended if 

 it would serve any useful purpose §. 



It will be noticed that all of these writers (as well as tliose who arrive at negative 

 results) iittempt to institute direct comjiarisons between highly specialized repi'esentatives 

 of tlie Carnivora like the Dog and Cat and the higher Apes. No writer has taken the 

 obvious precaution of testing the accuracy of his suggestions by an appeal to the simplest 

 and most generalized types in the two Orders : nor, again, is it altogether clear why tlie 

 vast majority of writers invariably seek for homologues for the sulci of the Primates in 

 only one Order of Mammals (in most cases the Carnivora), unless it be because the 

 non-Primate type of sulci is seen in its most sj)ecialized form in these latter. 



Every writer (including even those who, like Parker and Cunningham, deny the 

 homologies of the sulci in the Primates and other Orders) commits the fundamental 

 error of regarding the so-called Sylvian fissure of the Ciirnivora and other Mammals as 

 the representative of the Sylvian lissure of the Primates. But there cannot be the 

 slightest doubt that the two furrows are not homologous. 



The only means of arriving at any reliable conclusions as to the possibility of homolo- 

 gizing the sulci of the Lemurs with other mammals is to critically study the behaviour of 

 these furrows in the Mammalia as a whole. And as this is the only means of truly 

 appreciating the relationship of the Prosimian brain to that of other mamooals, I j^ropose 

 to bricHy summarize here the data relating to the cerebral sulci in other Orders wJiich 

 have been stated more fully elsewhere ||. 



Eirst of all, the behaviour of those sulci which I have represented in the Cat's brain 

 may be studied in the Carnivora. In the Primates, the two most stable furrows of the 

 neopallium, and those to make their appearance earliest in development, are the calcarine 



* " Die Winduiigen der convexcn Oberfliicho des Vorder-Hirns bei Menschen, Aften uud Itaubthiereu,"' Arch. f. 

 Psychiatrie, Bd. vii. p. 250 (1877). 



t ■' Anatomic coraparoe des circonvolution.s Co rub rales," Kev. d'Anthropologie, 1878. 



X " Bemerkungen iiber die Faltuugeu des Grosshirns uud ihrc Beschreibung," Arch. f. Psychiatrie, Bd. viii. 

 1878. 



§ Brief reviews of the Literature will be found iu memoirs by J. X. Langley ("The Structure of llie Dog's 

 Brain,'' Journal of Physiology, vol. iv. pp. 268-270) ; Jules Soury (" Systcmo Nerveux Central," tome ii., 

 especially pp. 910 & !Jlo) ; and Flatau and Jacobsohu (•• Vergl. Anatomic," op. cit.) 



II Catalogue of the lloyal College of Surgejus, Second Edition, vol. ii. 19U2. 



