306 C. JUDSON HEERICK 



DESCRIPTION OF FIGURES 



All of the figures are drawn from preparations of the brain of Necturus macu- 

 latus (Raf.). The figures of microscopic preparations are all drawn from single 

 sections unless the contrary is explicitly stated. The drawings made from 

 Golgi preparations aim to reproduce as faithfully as possible with pen and ink 

 the actual appearance of the sections. They are schematized only by the omis- 

 sion of irrelevant detail, and in a few cases (which are specially noted) some 

 features are introduced from adjacent sections. 



Figs. 1 to 14 A series of transverse sections through the thalamus and mid- 

 brain of Necturus, stained by the method of Weigert. The sections were cut 

 serially 15 n in thickness. The myelinated fibers are printed in blue and the 

 reference lines related to mj'elinated tracts are also printed in blue. X 25. The 

 serial numbers of the sections drawn are included in the descriptions (in these 

 and all other descriptions of figures the series numbers given refer to prepara- 

 tions of the brain of Necturus in the private collection of Professor P. S. McKib- 

 ben), from which the exact intervals between these sections can be readily com- 

 puted. Compare also figures 62 to 68, which are based on reconstructions from 

 sagittal Weigert sections. For the external appearance of this part of the brain, 

 see McKibben, '13, figures 1 and 2; see also the figures of Kingsbury, '95. Series 

 of sections through the cerebral hemispheres and thalamus of Necturus are 

 illustrated in the papers by McKibben, '11, and Rothig, '11a. Transverse sec- 

 tions through the upper part of the medulla oblongata are illustrated in figures 

 4 to 16 of my paper, '14, on the cerebellum of Necturus, and transverse sections 

 through the entire medulla oblongata of larval Amblystoma, which is very simi- 

 lar to Necturus, are figured in my paper, '14 a. 



Fig. 1 At the level of the optic chiasma (civ, 692). 



Fig. 2 At the level of the habenular commissure (civ, 703). 



Fig. 3 Through the thickest part of the chiasma ridge and postoptic commis- 

 sure (civ, 723). 



Fig. 4 Through the middle of the pars intercalaris of the diencephalon (civ, 

 733). 



