^y 



5. Heredity of Hair-Length in Guinea-Pigs 



AND ITS Bearing on the Theory 



OF Pure Gametes 



BY 



W. E. CASTLE AND ALEXANDER FORBES 



6. The Origin of a Polydactylous Race 

 OF Guinea-Pigs 



BY 



W. E. CASTLE 



Published by the Carnegie Institution of Washington 



May, 1906 



