BLOOD 



61 



The vascularity as observed for each lamina of the cortex 

 in each area is shown in chart 3. 



It is to be noted that in every area the maximum vascularity 

 is in IV^ — ^the lamina granularis interna — ^and that among the 

 areas the parietal is best supplied with blood vessels. 



Blood. Percentage of water in the entire blood and in the 

 serum. 



The specific gravity of the blood is 1.056 (Sherrington and 

 Copeman, 1893). 



Hatai ('18) has determined the percentage of water in the 

 entire blood of a small series of Albinos. These were from the 

 Institute stock grown on the scrap diet and examined before the 



TABLE 25 

 Percentage of water in entire blood of the albino rat at different ages {revised) 



day's feeding. The rat was chloroformed, but before the heart 

 ceased beating it was exposed in situ, the tip clipped away and 

 the blood from it caught in a small glass weighing bottle. The 

 fresh w^eight was immediately taken and after drying at 95°C. 

 for a week the weight of the residue was obtained. 



The results are given in table 25. These percentages are in 

 close agreement with our earUer laboratory records. 



Percentage of water in the serum. The data from Hatai ('18 b) 

 are given in table 27 and the graph for these in Chart 4. 



Resistance of red cells. The resistance of the red blood cor- 

 puscles at different ages to hypotonic solutions of sodium chlo- 

 ride shows fairly regular changes, Takenouchi ('19) table 26. 



