Some of the factors known to affect milk secretion are general health, food supply, psychic state, and heredity. The mechanism of secretion and the method by which these factors affect it are imperfectly understood. In general it has been observed that milk yield improves both in quantity and in quality with improvement in general health, better food supply, and more favorable psychic state. The influence of heredity is taken advantage of by dairymen who are well acquainted with the potential milk production of the different breeds of cattle. Among the substances which have been reported to stimulate milk secretion may be mentioned the extract of the posterior lobe of the hypophysis. But pituitary extract is not a true lactagogue, because its action is confined to the smooth musculature of the gland ducts, causing a more or less complete ejection of the milk already formed; it has no effect on the gland cells or the actual secretory process in the direction of increasing the milk yield. Extracts of thymus, corpus luteum, ovaries, uterus, placenta, fetus, and the mammary gland itself have also been reported to have a temporary stimulating effect on the quantity of milk secreted, but when these extracts are given by mouth they are apparently without specific influence on the mammary gland. Galega, or goat’s rue (_Galega officinalis_), is an herb described in the National Formulary as being slightly bitter and astringent. In 1873, Gillet-Damotti,[112] in a communication to the French Academy, stated that this plant when fed to cows increases the secretion of milk from 35 to 50 per cent. Other French writers have affirmed that goat’s rue is a lactagogue. In Germany, Fragner[113] made a preparation called Galegal, using galega as the active principle and combining it with lactose to give it a pleasant taste and make it soluble in water, milk, coffee, and tea. This preparation was reported on favorably by Scherer,[114] who asserts that he obtained positive results in fifty-four of the eighty cases in which he used it. [112] Gillet-Damotti: Comp. rend. Acad. d. Sc., July 7, 1873. [113] Fragner: Wien. med. Wchnschr. =60=:1033-1036, 1910. [114] Scherer: Wien. med. Wchnschr. =60=:1033-1036, 1910. More recently Huët[115] tested the effects of Theinhardt’s Hygiama lactogene on four lactating women. This preparation is said to be composed of hygiama,[116] galega and anise. Analysis showed that it contains albumins, fat, soluble and insoluble carbohydrates, salts and water. Huët could not observe any influence from the use of this preparation, either on the quantity or on the composition of the milk secreted. [115] Huët: Nederlandsch Tijdschr. v. Geneesk. =1=:1353-1370, 1914. [116] Hygiama is said to be a food consisting of condensed milk, with (fatless) cocoa and cereals added to it (Encyclopedia and Dictionary of Medicine and Surgery, 1907).