ACKNOWLEDGEMENTS 
To Professor A. B. Caine, the writer ex¬ 
presses his indebtedness for constructive criti¬ 
cisms and supervision of the work, while to 
Dr. H. D. Bergman he is under obligation for 
help given on the common and contagious dis¬ 
eases, and other troubles. The writer also 
wishes to extend his gratitude to the host of 
breeders whose kindly aid made the accom¬ 
plish of this dissertation possible. 
