WEIGHT OF EYEBALLS ON BODY WEIGHT 



91 



For convenience the graph for the spinal cord is given on the 

 same chart as that for the brain. The graph for the male only 

 is entered. For the same body length as the male the spinal 

 cord in the female is about 5 per cent heavier, and for the same 

 body weight, about 2 per cent heavier. Donaldson ('08, '09) ; 

 Hatai ('09a). 



Chart 9 Giving the brain weight on the body weight. Males only. Formu- 

 las (6) and (7), table 68. Also spinal cord weight on the body weight. Males 

 only. Formula (11), table 68. 



Weight of both eyeballs on body weight. Technic: Care being 

 taken to remove the muscle attachments, both eyes were 

 weighed in a closed weighing bottle. There is usually a close 

 similarity in the weight of the right and left eyeballs. The 

 graph is based on rats studied by Jackson ('13). His results 

 have been corroborated by studies on the stock Albinos from the 

 colony of the Wistar Institute, Hatai ('13). The values for the 

 graph in chart 10 and those given in table 68 are based on 

 formula (13). The graph for the male only is entered, but the 

 values for the female are like those for the male of the same body 

 weight. Under unfavorable nutritional conditions the weight of 

 the eyeballs follows the age rather than the body weight. Hatai 

 (MS '14). 



