1 6o 



C. Judson Herrick 



I I 



Ni 



IV 



VI 



.'I t. 



-V. I. 



-V. t. 



-b. oí 



-b.ol 



-bol 



far fonvard ventrally in the median plañe. Backward ¡t extends for a 

 short distance dorsally of the recessus neuroporicus and foramen inter- 

 ventriculare and for a longer distance ventrally of the foramen into con- 



tinuity with the nucleus preopticus, 

 which in its turn is directly connec- 

 ted with the hypothalamus. 



The three regions last mentioned 

 are connected by ascending and 

 descending fibers of the medial fo- 

 rebrain bundle in the typical verté- 

 brate manner (fig. 15). The área 

 medialis also sends fibers to the 

 área dorsalis of the same and the 

 opposite sides and to the habenula. 

 2. The área ol factoría dorsalis 

 (primordiuní hippocampi, Johns- 

 tonj is also greatly enlarged and 

 rolled inward or inverted so that 

 the áreas of the two sides coalesce 

 in the mid-dorsal plañe above the 

 recsesus neuroporicus (figs. 17, 18). 

 Its rostral part is separated from 

 the underlying área medialis by a 

 distinct cell-free zona limitans abo- 

 ve the recessus neuroporicus and 

 foramen. Posteriorly it extends 

 backward along the dorsal lip of 

 -b.ol. the telencephalon médium toward 

 sep. the habenula, with which it is con- 

 nected by a fiber tract which enters 

 the stria medullaris (fig. 15). 



The área dorsalis receives fibers 

 from the medial and lateral áreas 

 and from the tuberculum olfacto- 

 rium. It discharges fibers into the 

 habenula and is connected with the 

 hypothalamus by ascending and 



-b.ol 



/3 



Fig. 13. — Development of the form of 

 the telencephalon of Acanthias vulgaris 

 as seen in horizontal section, :< 7. 5. 

 Embryos of six ages are represented, 

 whose lengths are as follows: I, 32 mm.; 

 II, 36 mm.; III, 45 mm.; IV, 55 mm.; V, 

 83 mm.; VI, 92 mm. Modified from 

 Sterzi (1912, fig. 497). 



