Blood Relationahip and Learning. 



It was found that the learning ability of certain inerbera 

 of a groui could be predicted from the results obtained on other 

 nembera of the same litter. The data appear in Table XII. 

 Three rats from the YfC?) litter v/ere used when twenty-five lays 

 old, and five rats fron the sane litter worked when sij.ty-five 

 daj'S old. Two members of tlie G J litter learned the problem 

 at twenty-five days, and one at sixty -five days. Two A L rats 

 worked when twenty-five days old, and one when sixty-five days 

 old. ?our X L rats learned the problem at twenty-five days, 

 three at sixty-five days and three at two hundred days. 



The rats belonging to the YfC^) litter required a smaller 

 number of trials at 25 days than the average, but their absolute 

 time, total time and total distance were above the average for 

 rats of that age. At 65 days, rats of the same litter made 

 averaj^eo higher than the group averages for that age exce^ t for 

 the absolute time. The GJ rats twenty-five days old had a trial 

 and distance record higher than that of the entire group while 

 their absolute and total time was less. The same holds true for 

 the GJ rets at 65 days except that their absolute time is higher. 

 AT. rats show records lovver than the grorp averages in every case 

 at 25 days but at 65 days all of the AL averages are higher than 

 that for the group. 



iiats from the XL litter which worked at 25 days made low- 

 er records than the average except in absolute time. The same 

 is true of the 65 day members of the same litter and the 2C0 day 



