86 EMBRYOLOGY OF THE LOWER VERTEBRATES CH. 



The side wall of the hind-brain now conies to project outwards as 

 a prominent knob while the side wall of the fore-brain also bulges out- 



t.o 



thai 



D 



1. 



n.a 



Fie;. 51. Brain of young Lepidosm-n as seen from the dorsal iU-. 



A, htage81+ ; B. . 0, 8tag 88; I), adult. <.//, rrn-liral liniiis|iln'iT ; it.a, neural airli ; 



r ,u. ],incal Ix^ls ; -/<., rhi.inl'iii-<-]ih:ili)ii ; ///"/, tlialaiiiom-rplialoii ; t., It-rtinn <>/>ticiii,i. 1,11. Hi-., 

 cianial : I .-. A ami H an- more lii^lilv ma.nnilied Iliaii (', and Fin. (' Ilian 1>. | 



wards tin- IMI]-III : J in ihi> case Uung the rudimcni >!' i In- cerebral 

 hemisphere A .// 



The jiorlimi .!' ihc jiriinii ivc lin-r-lirjiiii Ivin^ .just in I'mnt u\' tin- 

 transverse fold <>l tin- l.iain-floor is the infundibulum. l-'.-n-tlu-r 

 forwards the inner surface <! tlie brain-llotn- fnnns a transverse 



