ILLUSTRATIONS 



381 



Figure 101.- — Semidiagrammatic sagittal section of the adult brain, Golgi method. X 35. 

 The section is oblique, with the dorsal side somewhat more lateral, cut in a plane which includes 

 almost the whole length of the lateral forebrain bundles and tr. olfacto-peduncularis. In the 

 tectal neuropil there are typical endings of the spinal lemniscus and tr. strio-tectalis (copied 

 from '42, fig. 17). 



nuc.bub. p 

 -br.t.p 



conn. tub 



104 



Figures 102, 103, /O^.^Three sagittal sections from the brain of a specimen from Colorado 

 prepared about two weeks after metamorphosis by the reduced silver method of Rogers. The 

 sections are slightly oblique, with the dorsal surface and caudal end more medial. X 37. 

 In this series of sections the courses of the tegmental fascicles can be clearly followed. These 

 pictures are selected from a series published in 1936. 



Fig. 102. — The section passes through the middle of the gray substance of the tectum op- 

 ticum at its widest part and shows the courses of the lateral forebrain bundles and lemniscus 

 systems ('36, fig. 17). 



Fig. 103.- — Section taken 0.17 mm. more medially and showing the arrangement of the more 

 medial tegmental fascicles ('36, fig. 18). 



Fig. 104. — Section taken 0.16 mm. more medially and about 0.1 mm. from the mid-plane 

 at the tuberculum posterius. It includes the interstitial nucleus of the f . longitudinalis medialis 

 {nuc.tub.p.) and the nuclei of the III and IV nerves ('36, fig. 22). 



