BRAIN AND SPINAL CORD OF RAT. 

 HENRY H. DONALDSON. 





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i I I L 







BODY LENGTH 



1 I 1 



mm. 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 



To show In the albino rat, the brain weight and spinal cord weight according to body length. (1) Upper entries, brain. Individual records, 196 males «, 137 females X. 

 curve is based on formula (8). (2) Lower entries, spinal cord, 189 males •, 137 females X. The theoretic curve is based on formula (3). 



210 220 



The theoretic 



The Jocrnal of Compabativb NEDEOLoat and Pstcholoot. — Vol. XIX. No. 2 



