1910.] VAIUETIES or MUS RATTUS IX EOVI'T. 0fi3 



brou<4lit ;il)Out by a multitude of naines is worse thiin tiie old 

 plan by which one name was made to cover all varieties. 



More recently still, the rediscovery of Mendel's theory has, at 



Text-tig. 62. 

 Length of Hind foot m mm. 

 15 16 17 18 f9 20 21 

 30 



25 



20 



o 



10 



Taiu-l; v.. 



Curve ot hiud-fuul. iiuaMirfmriits of Jcojiii/s rnhiriuus. to sliww siruiito curve 



I'or coiiipui'isoii witli ptcvious rahl':'>. 



