2I 4 



THK GROWTH OF THK BRAIN. 



horns in the cervical enlargement of the spinal cord. 

 The different species of animals which he examined are 

 named in the table. The cell -bodies were measured in 

 two diameters, and the mean of these measurements is 

 given in microns. The record in the table appears 

 under two heads, that exhibiting the diameter of the 

 chromophobic cell-bodies, or those staining poorly, and 

 that of the chromophilic cell-bodies, or those staining 

 well. This distinction is important because in the latter 

 case the cell-bodies have the smaller diameter. In this 

 locality, therefore, the chemical constitution varies with 

 size. 



TABLE 51. SHOWING IN A SERIES OF MAMMALS THE MEAN 

 DIAMETER OF CELLS FROM THE VENTRAL HORNS OF THE 

 CERVICAL ENLARGEMENT. THE MEASUREMENTS FOR THE 

 CHROMOPHOBIC AND CHROMOPHILIC CELLS ARE KEPI- 

 SEPARATE. (Kahcr.} 



MEAN DIAMETER OF CELLS IN 



i Bat. 2 Mole. 3 Monkey. 4 Rabbit. 5 Man. 



On passing from the bat up to man there is an 

 increase in the diameter, but this increase is by no means 

 proportional to that in the body-weight. While, there- 

 fore, the larger animals in this instance have slightly 

 larger cell-bodies, there is no constant relationship 

 between the diameters of the cell-bodies and the weight 



