36 



35 



37 



38 



39 



Fig. 35, a scale of grades for piebald rats. Fig. 36, a pair of piebald rats and their nine 

 young. Fig. 37, a smooth guinea-pig. Fig. 38, a well-rosetted rough guinea-pig, grade 

 A. big. 39, a poorly rosetted rough guinea-pig, grade C. 



