142 MR HAROLD AXEL HAIG ON THE 



alone appeared to give the best results. The Weigert-Pal method was given a trial, 

 but with negative results, owing to the special means of preservation and hardening 

 employed.* The following regions were studied histologically : 



(a) Mid-lumbar, dorsal, and cervical regions of the spinal cord. 



(b) Medulla oUongata: 



i. In the region of the pyramidal decussation. 



ii. At the lower level of the olivary body, 



iii. At the middle of the olivary body, 



iv. At the upper level of the olivary body. 



(c) Pons, lower, middle, and upper regions. 



(d) The mesencephalon : 



i. At the level of the posterior corpora quadrigemina. 

 ii. At the level of the anterior corpora quadrigemina. 



(e) The optic thalamus. 



(/) The motor region of the cortex of the cerebral hemispheres (precentral gyms). 



(g) The cerebellar vermis (mesial region). 



(k) The optic chiasma. 



(i) The pituitary gland. 



(k) The uncinate gyms of the hippocampus major. 



I. HISTOLOGY OF THE SPINAL CORD. 



A. Cervical Region. (Text-fig. 1.) 



A transverse section across the upper region of the cervical cord shows a very 

 marked breaking up of the grey matter into four main groups in each half, viz. : 



(a) A posterior mass extending from the posterior grey commissure into the 



posterior median column of Goll ; in this mass at the base small nerve-cells 

 are seen, and a few at the peripheral part near the surface of the cord. The 

 latter represent the beginning of the nucleus gracilis, which soon becomes 

 prominent even in the cervical region. 



(b) A postero-lateral mass, into which the fibres of the posterior roots may be seen 



to extend. In this mass small nerve-cells may be made out, but they are 

 very scattered and not at all conspicuous. 



(c) An intermedio-lateral mass, at the central portion of which some large nerve- 



cells are to be made out, these representing the cells of Clarke's column. 



(d) An anterior mass (anterior cornu) of wide extent, and possessing four or five 



groups of very large nerve-cells (motor cells of anterior cornu). 



* The pituitary gland sections were stained with Delafield's h;nnatoxylin, followed by eosin to differentiate. 



(UOY. SOC. EDIN. TRANS., VOL. XLVIII., 850.) 



