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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1916 Excerpt:... of white spotting.10 A considerable number of red-and-whites that breed true have been obtained in this manner. To produce black-and-whites which breed true a somewhat similar procedure is followed. In this case we want to introduce the E factor, which causes the black to be extended throughout the pigmented part of the coat. This is done by crossing a self black (EESS, figure 1, type 1) with an cc red-and-white. The F/s will all be self black. Their composition will be EcSs. When they are inbred we should expect one out of sixteen of the offspring to have the composition EEss (figure 1, type 3). These would be the black-and-whites which breed true. We have obtained animals of this kind by following the above method. One of them, t? 356.3, when mated to other black1and-whites had 20 offspring, all black-and-whites. When mated to ce red-and-whites, he had 18 offspring, all of which again were black-and-whites. We have neglected to mate EE black-and-whites to self reds, but we have made a mating using an Ec black-and-white. The resulting offspring consisted of 9 self blacks and 8 self reds. EE black-and-whites mated to self reds should get all self black offspring. From the foregoing at least two methods can be derived whereby ep black-and-whites can be distinguished from black-and-whites carrying the E factor. Inspection of the third type of mating in table 4 will show that when r'V black-and-whites are mated to cc red-and-whites tricolors tend to make up a majority of the offspring. In a similar kind of mating when EE black-and-whites are used, all of the offspring are black-andwhites. The above is the first method. The second method, which requires fewer offspring to determine the point at issue, consists in mating the black-and-whites to be tested to sel...