1 56 



but so much is true (coinp also Kinnier Wilson's ') experiments and the clinical 

 cases) that the integrating tonetic factor may have an important role in this. 



That also visceral disturbances may occur (liver, bladder) in diseases of the 

 corpus striatum and that sympathetic functions have been found to exist here is 

 not so strange in connection with the fact that the primitive striatum developes 

 near the frontal end of the sulcus limitans (which according to several authors, 

 c. f. Herrick) ends in the preoptic recess. Moreover we know from the research- 

 es of BoEKE. DussER DE Barenne, Agduhr and the Boer that also in muscle- 

 tonus sympathetic fibres may act a part. 



Since visceral and tonetic conditions act an important part in emotions, I 

 would moreover not be astonished if the striatum would prove more and more 

 to have to do with emotions. 



Al last the que.stioii remains if also the hy perstriatum superius of 

 birds is included in the neostriatum of mammals and man. 



This problem is not easy to solve. One might be inclined to 

 believe that this region of the avian brain is more likely related to the 

 mammalian claustruin, a supposition I already inade in my textbook. 



As the hyperstriatum snperins, the claustrum is entirely ofpallial 

 origin. Though it may not be derived from (the sixth layer of) 

 the cortex, yet all its cells are derived from a pallial matrix. De 

 Vries') has clearly shown (hat the claustrum in embryologie stages 

 does not derive from the cortex, but that it deiives from the lateral 

 brainwall (which at this spot must be called pallium) between the 

 upperedge of the neostriatum and the cortical layers, separated from 

 the latter by fibres of the capsula exlrema. 



Also the figures given by Landau ') in his anatomy of the fore- 

 brain shows that the way the claustrum developes is that of an 

 intraventricular growth of the pallium (a hypopallial growtli in the 

 sense of Ell. Smith), though apart from the cortex. In its mode of 

 formation the claustrum thus resembles the hyperstriatum superius. 



Still in another point there is resemblance between both. Whereas 

 the neo-striatum in mammals (like the hyperstriatum inferius in 

 birds) developes partly from the base of the brain immediately 

 behind the olfactory bulb, partly from the pallium lateral to the 

 olfactory bulb, the hyperstriatum superius like the claustrum only 

 developes from the pallium starting in front immediately above the 

 anterior olfactory lobe of the avian brain. 



The fact that the claustrum is very small in Monotremes and 

 Marsupials (where it extends, as in many mammals, partly under- 



1) An experimental research into the anatomy and physiology of the corpus 

 striatum. Brain Vol. 36, 1913-1914. 



■'t Bemerkungen über Ontogenie und vergleichender Anatomie des Claustrums, 

 Folia Neurobiol. Bnd. IV, 1910. 



') Die Anatomie des Grosshirns, Bircher, Bern 1923. 



