157 



neati) tiie tiss. rliinalis \iz. fioni tiie region wliich is covered by 

 the palaeopalliuin) and only in primates attains a size comparable 

 to birds, does not necessarily contradict this homology, since there 

 there are more respects in which the human brain resembles more 

 the a\ian brain than the lower mammal» do, f. i. in its oculo- 

 motor nucleus (comp. A'ol. II of my book fig. 261 with figg. 294^295). 



Moreover there seems to be a considerable difference in the deve- 

 lopment of hyperstriatum superius also in birds. As a matter of fact 

 1 have not been able to see it in the Kiwi (see Hunter's work on this 

 peculiar bird ') (to be published in the English Journ. of Anat. 1923—24). 



In the casuary, and the ostrich it is [tresent, but not yet in the 

 same size as in tiie chick. 



Tiie bloodsupply of tiie iiyperstriatum superius is not in contra- 

 diction with such a homology, since the hyperstriatum superius next 

 to many branches of cortical vessels, leceives a few branches of 

 the basal arteries, as Shellshear ') proved to be also the case with 

 the claustrum of mammals. Perhaps that also the function of these 

 regions shows a certain relation in so far as degeneration of the 

 claustrum seems to give incoordination of movements (athetosis) 

 while also in experimental degeneration of the hyperstriatum superius 

 disturbances of motor function occur (Rogers). The question may 

 certainly not he considered settled as yet, but the possibility may 

 be kept in mind that tiie hyperstriatum superius is not involved 

 in the neostriatum of mammals, but in their claustrum, though 

 this region of the telencephalon in birds has taken a development 

 which in this form and size may be peculiar to these animals only 

 just as the large development of the primary epistriatum is peculiar 

 to Teleosts and Ganoids. 



CONCLUSIONS : 



Resuming we may state that also the comparative ontogeny of the 

 striate complex in (Reptilesj, Birds, Mammals, and Man proves that 

 apait from the secondary epistriatum or archistriatum (amygdala) two 

 chief parts may be distinguished: palneosiriatum and the neosti-iatwn, 

 which are separated from each oüiev by Ihe lamina 7nedull(ii'i.i externa 

 (richly provided with bloodvessels) and iba jïssHra-neo-palaeostriatica. 



1) In connection with this it is interesting to note tliat in Parker's figures on 

 the embryology of the Kiwi brain (see Tiansactions of the Roy. Soc, London) 

 Vol. 182, 183, 1892 and 1893), only two intraventricular primordia (my b and c, 

 are drawTi, and d the primordium of the hyperstriatum superius seems to be 

 lacking here). 



') The basal arteries of the forebrain and their functional significance, .lourn. of 

 Anatomy (English), Vol. .55, 1920. 



11* 



