ON DISTRIBUTION OF THE CELLS IN THE INTERMEDIO-LATERAL TRACT. 121 



CL-rn 



'ig. 13 (D. 8, 112, R. ). — The reticular group of cells ex- 

 tends backwards behind Clarke's column. It is in- 

 definitely bounded on its inner side. The apical group 

 is small and shows several distinct outlying cells. 



Fig. 14 (D. 8, 370, L.). — The apex of the lateral horn is at a 

 level posterior to the central canal. The reticular cells 

 lie almost entirely behind the level of the column of 

 Clarke. The reticular and apical groups are almost con- 

 tinuous, and they are indefinitely bounded on their inner 

 side. The reticular cells form a sort of wedge which 

 points towards the front of the column of Clarke. 



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Fig. 15 (D. 9, 168, L.).— The lateral horn with its bluntly 

 pointed apex lies behind the equator of Clarke's column. 

 The altered shape of the horn, with its reticular group 

 lying internal to rather than posterior to the apical 

 group, is shown. The two groups are continuous, and 

 there are several outlying cells near the apical group. 



Fig. 16 (D. 9, 413, R. ). — The lateral horn shows a sharp apex, 

 directed backwards and outwards, and lying at the level 

 of the posterior half of the column of Clarke. The apical 

 group is distinct and is continuous with the reticular 

 group. 



TRANS. ROY. SOC. EDIN., VOL. XLV. PART I. (NO. 5). 



16 



