It is necessary to ijreserve these figures in oriier to compute 

 the total daily averages based upon v/hich the curves of leai-n- 

 in£_ are constructed. The particular value of tables IX nnd X 

 is that they tiive the data in deta,i3 fron which the tables 

 of comparative summaries are constructed. 



In table XI is presented a comparative summary con- 

 eistinti of the daily avera(j,es of all the inbred and aD 1 the 

 control rats used in the inclined plane experiment. From this 

 table are constructed the comparative curves of learnint^. The 

 table shows that eleven of the inbred and two of the normal 

 rpts failed to learn the inclined plane. The inbreds required, 

 on the average, "7?. 70+ daj/-8 to learn; the normals but 45.97-f. 

 The absolute retention of the inbreds was, on the averai:,e, 

 31.842 seconds; of the normals, 22.587 seconds. All the inbreds 

 had relearned at the end of the tv/enty-f ourth day; but all 

 the normals had relearned at the end of the seventeenth day. 

 The inbreds required, on the averae;e 6.74 days to relearn; 

 the normals but 4.68, 



In all these criteria of ability the rats of the 

 normal control series are shown, on the avera.^e, to be supei-- 

 ior to those of the inbred series. 



The body length of the inbred rats \ised in the in- 

 clined plane is, on the averaj^e a trifle ^-reater than that 

 of the normals; the body weight is slightly less. The avera^je 

 'ictual brain wei^jht of the inbreds is less than that of the 

 normals. The relative brain weitjht (in reference to body length) 

 of the inbreds is 5.89;' less than that of the normals. The 

 relative brain weight (in reference to body weitrht ) of the 

 inbreds is 2 . ."^Bf^ less than that of the normals, i^lthout^li the 

 inbred rats were killed, on the averat^e, at a more advanced 

 age than the normal control, the percentat.e of water in brain 



