According to Chesnut, goats may eat quantities of _Euphorbia Lathyris_, and it is said that their milk then possesses the poisonous properties of the plants. Ingestion of other Euphorbias appears to have the same effect. Cornevin remarks that _Melampyrum arvense_ is considered to influence cows to produce more milk. According to some authorities species of _Equisetum_ check milk production or cause it to cease, and _E. palustre_ is stated by Weber to cause the milk of affected cows to become watery, poor in fat, and give rise to a greasy and unappetising butter, while the yield may soon quite fail. The ingestion of the foliage of the oak (_Quercus_ sp.) is stated by Cornevin to induce _Maladie des Bois_, with reduction or entire loss of milk production (see p. 69). Acorns have also affected milk production, and a case is recorded (_The Dairy_, 1913) in which it is stated that cheese made from the milk of cows which had fed on acorns developed a sharp acid flavour when about four weeks old, though the texture was good. It is not clear, however, how it was proved to be due to the acorns. In one case recorded a reddish tinge was observed in the milk of a cow suffering from Rhododendron poisoning (p. 46), and in general reduced milk production appears to occur. In addition to the foregoing, there is good authority for saying that the following plants may impart a disagreeable flavour to milk, and in many cases the butter made from it:— _Anthemis arvensis_L. (Corn Chamomile). _Anthemis Cotula_L. (Stinking Mayweed). _Artemisia Absinthium_ L. (Wormwood). _Conium maculatum_ L. (Hemlock). _Hyoscyamus niger_ L. (Henbane). _Matricaria Chamomilla_ L. (Wild Chamomile). _Pinguicula vulgaris_ L. (Butterwort). _Senebiera didyma_ Pers. (Lesser Wartcress). _Sium angustifolium_ L. (Lesser Sium). _Sium latifolium_ L. (Water Parsnip). _Tanacetum vulgare_ L. (Tansy). _Thlaspi arvense_ L. (Penny Cress). (See also Index “Milk, plants affecting,” p. 117.) PLANTS WHICH CAUSE MECHANICAL INJURY.