117 



foand in the anterior divisions of the briin. It is not dis- 

 similar to a fideiy spreading bush, the cell-body bein^ the 

 short stem, and the dendrites the top (Pi^.23), The denJrites 

 are thick at their bases, they give origin to only a few branch- 

 es, they taper gradually, and their tips usually reach almost 

 to the limitans externa. The surface of a dendrite exhibits a 

 multitude of spiny gemmules of various sizes. 



The course taken by the axone depends upon the position 

 of the neurone. A neurone lying in the r-oof gives off its 

 axone from the base of the cell, and the axone passes ventral- 

 ly, branching profusely (Pig.?7). A neurone from the side- 

 wall (F'ig.SB) invariably has its axone emerging from the side 

 of the cell, taking a course toward the limitans externa for 

 a short distance, then branching in a T-shaped manner. The 

 fibres thus formed run parallel with the surface of the brain, 

 one tarning into the ventral part of the lobus, the other pur- 

 suing an arcuate course out of the hypothalamus (Pig. 27, f.b.). 

 Such a fibre is marked by varicosities at intervals, and it 

 bears collateral branches (Pig. 83). 



The internal structire of two neurones from the lobus 

 inferior is given in Pig. 54. Tne figure also shows how close- 

 ly these neurones are packed. The nucleus is only fairly large, 

 and it is surrounded by a thick layer of cytoplasm on all sides, 

 the chromatic substance is scanty in amount; it is distriluted 

 in a few thin strands. The tigroid nasses are not numerous, 

 and most of them are ouite sn.all. witl; Just a few lart^e ones 



