821 



commissure and cross to (lie otlier side i\^ \\ie fractiis stno-thalamicus 

 rrucialH.t hiterims (Fig. IX). Here liiey join the liomoiateral fibres of' tlie 

 opposite side [tractus strio-thalandcus rectus internus). The destination 

 of these fibres in birds, as shown by Edinger and Wallenbekg 

 (1899^ is the ventral thalamus and mid-brain. 



/'. Hypophysis mid Epiphysis. 



The hypophysis extending ventrally contains a funnel shaped 

 prolongation of tlie median ventricle (fig. 8). 



The epiphysis thoiigli damaged is clearly recognisable in a series 

 of the sections. 



IV. General suniniary. 



The brain of the kiwi,, for tiiat of a bird, is remarkable for the 

 great development of its olfactory lobes. In contrast with this the 

 visnal connexions are mnch rednced. Externally the nsnal subdivision 

 of the avian cerebral hemisphere into pars viedia/is and i)ars 

 lateralis cannot be seen. 



A study of sections sliows that the olfactory bnlbs and lobes 

 present a typical bnlbar formation. Tlie a7'ea praepirifonnis, the 

 nuclei of the septum, and the Area 28 of Rose are recognisable. 

 In accordance with the great development of the smell apparatus 

 the ventral forebrain bundle, the fronto-epistriatic tract, and the 

 olfacto habenular tracts are well developed. Accompanying the 

 olfacto-habenular tract is the commissnra telencephali superior which 

 is usually not seen in birds. 



As is usual in birds the corpus striatum forms the major part of 

 the cerebral hemisphere. The natural subdivison of the striatum is 

 clearly revealed in the kiwi. The archistriatum (secondary epistriatum) 

 can be recognised by the fact that it receives the frontd-epislriatic tract 

 and is connected to its fellow of the opposite side by the inter-epistriatic 

 commissure which is a conspicuous constituent of the co7n7nissiira 

 anterior. The paleostriatum consists of the basal \\\\óe\\s,{palaeostriatnm 

 />rimitiviim) and mesostriatum ( pa I aeostriatuin augvuntaium). The 

 mesoslriatum in separated from the hyperstriatum by the external 

 medullary lamina which extends from the ventricle medially lo the 

 ventral surface of the hemisphere, the line of separation here being 

 indicated by the fissvra ventralis. Vessels (hyperstriatal artery) enter 

 this groove and accompany the external medullary lamina. These 

 vessels are homologised with the lateral striate artery of reptiles 

 (Elliot Smith) and the daustral artery of man (Shei,lshear). Tiie 



