When the pig is about three months old its temporary teeth are all in position, the temporary lateral incisors are through, and nearly as long as the temporary central incisors. Owing to the lengthening of the jaws the two temporary corner teeth which were present at birth will have become further apart. When the pig is about five months, the fourth molar in either jaw shows itself in the gums, then at six months the wolf teeth show between the tusks and the premolars, and the fourth molar is nearly level with the first premolar. The corner incisors and the tusks usually disappear, and are replaced by permanents when the pig is nine months old. The second permanent molar also shows itself. At twelve months the two central temporary incisors give place to the permanents; these last are more square in form than the temporaries, and are thus easily distinguished. The three temporary molars will also be ready for displacement by three permanents. These last will be level with the other permanent molars when the pig is fifteen months. The two lateral incisors will also have given place to permanents. At eighteen months the third permanent molars will be coming through, and at the age of twenty months the pig's teeth are fully developed. CHAPTER V SELECTION OF THE BOAR The hackneyed saying "The sire is half the herd" appears to have a different meaning to varying persons. To some it conveys the idea that the selection of the sire is of far more importance than the selection of the dam because the influence of the sire is so much more powerful than that of the dam on at least the external form and character of the produce. The late Mr. James Howard, who took a particularly keen interest in the breeding of pigs, used to declare that the appearance and form of the young pigs far more generally followed those of the sire than of the dam; whilst the influence of the latter was more shown in the character and constitution of their joint produce; or in other words, that the boar stamped his character to a greater extent on the external points of the young, whilst the sow more strongly influenced the internal parts of the youngsters. It is quite possible that this idea has gained ground to a large extent from the fact that the use of a pure bred sire on ordinary or grade females has been very much more common than the crossing of pure bred females by the ordinary or non-pedigree sire; as also from the far greater numbers of young which each pure bred sire would improve, than would be improved by each pure bred female which might be crossed. If only for this reason alone, we would always recommend buyers who are desirous of grading up and improving their farm stock to attempt to do this by the purchase or use of the pure bred or improved sire. The original outlay is infinitely less, whilst the immediate results are comparatively longer.