142 



Examining llie same series on a more lateral le\ei (lig. 7), we 

 meet with the hyperstriatum superius d, and see that this arises 



from the mantle only, i. e. 

 from the brain wall above 

 the small split that indicates 

 the commanicatioii between 

 the lateral ventricle and the 

 olfactory ventricle (already 

 in fig. 6 the frontal part of 

 the pallium shows a thicke- 

 ning at this place). 



Ill the last section of this 



series which I reproduce 



(fig. 8), all the |)arts of tlie 



striatum complex of birds 



Fig. 5. Sagittal section of the forebrain <ii"e already visible in their 



of a chickembryo of S'/j days, mutual arrangement : the 



Ö = primordium of the palaeostriatum. hy perstriaium superius (d.) 



,-o. = wall of the recessus opticus. fonning the most dorsal part 



and extending over the rest, being continuous fronlally with the pallium. 



Underneath it we find the hypeistriatum inferius c being in this 



Fig. 6 Sagittal section of the forebrain of a chickembryo of 6 days 

 on a level lateral to fig. 5 



t.p. = tuberculum parolfaclorium, t. o. = tuberc. olfact. 

 b = palaeostriatum augmentum, c = hyperstriatum inferius. 

 (= mesostriatum). 



