As osseous cachexia of oxen occurs in certain well-defined districts in France, and seems due to the feeding, why does it not attack horses in the same regions in an enzootic form? The answer appears to be that horses receive a greater amount of rich food, particularly of cereals, which contain much larger amounts of mineral salts, including phosphates, than does ordinary forage. The most serious objection was made by Tapon, who states that in 1893 he saw osseous cachexia in oxen on farms in La Vendée where superphosphate had been used for years, whilst the disease did not exist on other farms where such chemical manures were not employed. Before attaching much weight to this objection, however, it would be necessary to know the richness in phosphoric acid of the soil on the respective farms, for it is possible that, in consequence of natural conditions and in spite of the use of certain mineral manures, the richness of the soil on the first-mentioned farms, though manured with superphosphates, was still below that of the others which had received no artificial, manure. The system of culture is also of importance, for at the present day, even with the use of artificial manures, cropping would rapidly impoverish soils which were not suitably and sufficiently enriched. Abundance or apparent richness of food signifies nothing if quality is lacking. It may also be asked: if the question of nourishment is of such prime importance why are animals of European origin in Cochin-China affected, whilst the indigenous races prove immune? The answer would appear to be that, in addition to the defective quality of food, other factors, such as adaptation to environment and relative digestive power, play a considerable part in the production of the disease. =Favouring causes.= Whilst conceding that the disease is due to one determining cause, viz. the food, it is unquestionable that other causes may favour its appearance. Abundant milking is one, so that the disease most frequently appears six to eight weeks after calving. Gestation may also determine an attack. The disease is rarer in oxen than in milch cows. Starvation and bad hygienic conditions also have a certain influence; it is well known that during dry years, particularly when fodder is scarce, osseous cachexia makes the greatest ravages. Law states that the disease has been attributed to excess of organic matter in the soil, to succulent watery foods, as rank watery grasses, potatoes, turnips and other roots deficient in nutritious solids. Some agent—microbe or toxin—swallowed with the food has been suspected but not yet isolated.