448 C. JUDSON HERRICK 



The relations of the ventro-median part remain practically 

 unchanged except for further growth beyond the lamina terminalis. 



The ventro-lateral part is as directly continuous with the pars 

 ventralis (prominentia fascicularis) of the thalamus as in the larva. 

 The elements of the primordial corpus striatum are more completely 

 evaginated than in the larva; nevertheless the caudal end of this 

 complex still remains behind the interventricular foramen in 

 intimate relation with the lateral forebrain tract in the unevag- 

 inated wall in the same morphological level as the eminentia 

 thalami of the larva. 



The pars dorsalis thalami is greatly enlarged in the frog and its 

 whole lateral surface is differentiated as corpus geniculatum 

 laterale to receive collaterals and terminals of the optic tract. 

 The fiber connections of the thalamus are essentially as already 

 described for the urodeles (pp. 433, ff.), save for a much larger 

 proportion of optic projection fibers from the corpus geniculatum 

 laterale in the lateral forebrain tract, and also a larger compo- 

 nent from the midbrain. 



Gaupp ('99, p. 80) gives a very clear analysis of the walls of the 

 diencephalon. He divides the central grey of the thalamus into 

 habenular ganglion and superior, medial and inferior parts. The 

 last belongs in the hypothalamus and the superior and medial 

 parts correspond with the pars dorsalis and pars ventralis thalami 

 of my description. The sulcus diencephalicus dorsalis is present 

 and also the sulcus medius. Gaupp does not name these sulci, 

 but gives to the cell-free zone bordering the sulcus medius the 

 name zona limitans superior. The sulcus diencephalicus infe- 

 rior is absent, but its position is marked by a similar " zona limitans 

 inferior." Gaupp correctly describes the pars dorsalis (superior) 

 thalami as ending in attenuated form rostrally of the habenula, 

 and the pars ventralis (his medialis) as extending forward into 

 the nucleus supracommissuralis, or nucleus of the hippocampal 

 commissure. 



