PREFATORY STATEMENT. 



About twenty years since, we discovered the origin of 

 the Yield Mark — escutcheon — on Milk Cows. But the ex- 

 citement of the war and other matters incident to a farm- 

 er's life, such as changes of residence, and poor health, 

 prevented any thorough consideration of the escutcheon 

 mystery of Guenon till in 1868. In that year we ex- 

 plained the origin of the Yield Mark to the late Hon. W. 

 C. Flagg, of Moro, Illinois, who suggested a revision of 

 Guenon's Treatise. But on looking more closely into it, 

 we found nothing worth the labor of revision — only a fic- 

 titious system erected upon the coincidence of yield, with 

 the size of the Yield Mark as its sole foundation, which 

 seemed to us quite insufficient to build a labored system 

 upon. Instead of revising, we wrote a dozen chapters on 

 different phases of, the subject and its adjuncts, but finding 

 other matters of value accumulating rapidly, we reduced 

 the treatment of the Yield Mark, and its relation to yield, 

 to the two chapters specially devoted to it, adding a num- 

 ber of diagrams. 



In 1868, soon after the reports of Doctors J. C. Dalton 

 and W. H. Carmalt to the New York State Agricultural 

 Society, on the subject of "Abortion in Cows," and "the 

 negative results of the commission's investigation" were 



