PREFACE TO THE FOURTH EDITION xi 



haustively dealt with. Their common diseases have been 

 fully though briefly described, and the remedies to be used 

 in each case stated. In this part of the work thanks are 

 due for much appreciated help to Sydney F. Pennington, 

 B.Sc. (Edin.), M.R.C.V.S., now of the Agricultural School, 

 Ghizeh, Egypt ; and to Wm. R. Davis, M.R.C.V.S., Enfield. 



To friends, too numerous to name, who have assisted in 

 reading part or the whole of the proofs, I have pleasure in 

 recording grateful thanks. 



The half-tone process-blocks have been reproduced from 

 a unique collection of photographs of picked animals, repre- 

 senting the different breeds ; and in every case where 

 known, the name of the photographer, whether amateur or 

 professional, has been given. To mention the fact that 

 the work was executed by Hislop & Day is a sufficient 

 guarantee of its quality. We cannot refrain from acknow- 

 ledging the great additional interest which is attached to 

 a book of this kind by the products of the camera. 



It is a great gratification to the Author, and it will also 

 inspire confidence in the general public, to know that the 

 printing and publication of the Fourth Edition has returned 

 to the old-established firm of Oliver & Boyd, Edinburgh, 

 under whose auspices the first two editions acquired world- 

 wide success. 



ROBERT WALLACE. 



UNIVERSITY, 

 EDINBURGH, June 1907. 



