137 



This increase in thickness gives rise — a little more caudaliv 

 than fig. 3 — to a large mass of nervous tissue, extending over 

 the palaeostriatnui (which itself is derived from the basal part) and 

 therefore lias been named by Edingek epistriutum . 



Edingeh himself thongiit that this epistriatiiin is an outgrowth of 

 the striatum. 1 iia\ e however been able to show that it reallj is 

 caused by a medial thickening of the pallium extending over the 

 palaeo-striatum. Also by studying its fibre-connections — which 

 appear to be lu)mologous to the fibre connections of the selachian 

 mantle — I have been able to show this homology. ') Referring 

 for further details concerning the Teleostean brain to the works of 

 Johnston '), SntaooN *), V.an der Horst *) and Holmgren '), I will 

 only call the attention to the fact that this e|iisiiiatum of fishes has 

 chiefly primary olfactory functions, viz. that it receives chiefly 

 fibres of the ti-. olfactorias (fibrae bnlbo-epistriaticae). in this sense 

 it is a primary epistriatum. 



A primary epistriatum also developes in Amphibia but it remains 

 very small there ^receiving only tr. olfact. fibres from the bulbus 

 accessorius *)) since the surface growth of liie mantle is so consider- 

 able in Amphibia. This jirimary epistriatum of Anipiiibia developes 

 entirely independently from tlie palaeo-striatum or basal nucleus, in 

 front of it, from the side wall of the forebrain. 



In Reptilia the primary epistriatum is superposed by a much 

 larger secundaria epistriatum or archistriatnm i. e. by an ingrowth 

 of the mantle which does not receive bulbo-epistriatic fibres but 

 loho-epistriatic, i. e. secundary olfactory fibres from the primary 

 olfactory cortex (paleocortex mihi ; cortex praepiriformis Brodmann). 



Notwithstanding its enormous development and intraventricular 



'I The structure of the Teleostean and Selachian brain. Journ. of Comp. Neur. 

 Vol. XVI, 1906. Zur vergleichenden Anatomie des Vorderhirns der Vertebraten, 

 Anat. Anzeiger Bnd. XXX, 1907. 



-) The telencephalon of Ganoids and Teleosts. Journ. of Comp. Neur. Vol. XXI, 

 1911 and the Teleostean Forebrain, Anat. Record. 1912. 



3) The olfactory tracts in Teleosts. Journ. of Comp. Neurology Vol. XXII, 1912. 



*) The forebrain of the Symbranchidae. Proceedings of the Kon. Akademie v. 

 Wetenscli. Amsterdam, 1920. 



») Zur Anatomie und Histologie des Vorderhirns und Zwischenhirns der Knochen- 

 fische, Acta Zoologica, Bnd. I, 1920. 



*) Herrick. The morphology of the forebrain in Amphibia and Reptilia. Journ. 

 of Comp. Neurol. Vol. XX, 1920. 



De Lange. Das Vorderhirn der Reptilien, Fol. Neurob. Bnd. V, 1911. 



Arïens Kappers und Hammer. Das Zentral-Nervensystem des Ochsenfrosches 

 (Rana Catesbyana) Psych, en Neur. Bladen 1918. 



