THE WEIGHT OF THE BRAIN AND SPINAL CORD. 



93 



another in the zoological scale. As has been previously 

 explained, the white matter is more homogeneous than 

 the grey, and the percentage of water in the white 

 matter therefore shows the least variation. The order 

 in which the animals stand in this table was determined 

 by putting first the one with the smallest percentage of 

 water in the grey matter of the cerebrum and letting the 

 others follow in regular succession. Passing from the 

 monkey to the dog, cat, and man, the percentage of 

 water increases in the other portions of the nervous 

 system much as it does in the grey matter of the cere- 

 brum, since the proportion of cell-bodies increases. 



In looking at the subdivisions of the spinal cord as 

 made for this examination, it is to be remembered that 

 proportionately the cervical and lumbar regions contain 

 more grey matter than the thoracic region does, and as a 

 result both those regions show the greater percentage of 

 water. Since in the lumbar enlargement the proportion 

 of white matter is less than in the cervical, we should 

 expect, as the records show, that it would contain the 

 greatest proportion of water. Using a similar method 

 to that of Halliburton, De Regibus obtained in Italian 

 brains the following figures, which apply, however, to 

 the cortex and white matter of the cerebrum only. 1 



TABLE n. SHOWING OBSERVATIONS BY DE REGIBUS (GiA- 

 COMINI) ON ITALIAN BRAINS. THE FIGURES INDICATE THE 

 PERCENTAGE OF WATER IN THE GREY AND WHITE MATTER 

 OF THE MANTLE OF THE CEREBRUM. 



1 Vide Giacomini, Guida, &c., Torino, 1884. 



