(6) The keeping of a special bull for serving animals which have aborted, or, what is based on the same idea, the disinfection of the external genital organs of the bull with antiseptic solutions after he has served such a cow. (7) Destruction of the abortion membranes, and disinfection of the parts of the buildings, litter, etc., with which the infective material has come in contact. (8) The keeping of a goat, especially a male goat, in a byre with the cows." It cannot be said of the above measures that either singly or collectively they have brought about any material improvement in the general condition of our herds in relation to abortion. According to reports, decided improvements have been effected in individual herds by the adoption of isolation and disinfection, while in others very little has been accomplished. Some of the above methods are founded on nothing more than ignorant empiricism, while others are based upon pathological and physiological considerations which are only partially correct in their applications. Since most of them have obtained a certain amount of hold, at least on the minds of stockowners, it may be useful to discuss each measure separately in the light of our recent investigations. _Spraying of the External Genital Organs._--This is a procedure which probably has little or no value. (_Abridged._) _Isolation of Animals as soon as they show Signs of Abortion._--The necessity for this measure is obvious, and its importance cannot be too much insisted on. An infected animal only becomes infective to others immediately before the act of abortion, and may remain so for some weeks afterwards. However, only a proportion of the affected animals show premonitory signs, and quite a number may abort amongst their companions without warning. Under such conditions, then, measures of immediate isolation lose much of their undoubted theoretical value, owing to the difficulty in the way of carrying them out in practice. There is not likely to be any serious difficulty in diagnosing the bacterial disease after an act of abortion, even in an isolated case, if the membranes are available in a reasonably fresh state. (_Abridged._) Isolation of the affected animals, however, must be complete before and after the act to be of any real value. Having regard to what appears to be the most common form of infection, viz., by ingestion, we do not think that anything material is to be gained by merely putting all the cows about to abort and those which have aborted at the lower end of a byre, so that the infective discharges may not come in contact with the external genital organs of their fellows, unless we assume that infection frequently takes place by an animal licking virulent material from a part of its body where it has been deposited by flicks of the tail which has been contaminated by lying in the gutter behind the stalls.