Leroy S. Palmer

The nature of the substances adsorbed on the surface of the fat globules in cow's milk. (Preliminary Report).

It is possible to account for the emulsion character of the fat in milk and cream both on theoretical grounds, because of the abundant presence of hydrophilic colloids in milk plasma, and on experimental grounds, because milk plasma (skim milk) readily stabilizes emulsions of oils and fats foreign to milk. However, a number of investigators, beginning with Danilewski and Raden-hausen, 1 have attempted to isolate the emulsifying substance from milk. Storch 2 concluded, as the result of extensive experiments, that a special substance, a mucin-like protein, is involved. Völtz and Abderhalden 3 and Völtz 4 decided against the existence of a special substance because of the wide variety of products of varying proportions isolated by them. More recently Bredenberg, 5 who, like Völtz, gives a very complete review of the literature, concluded that a mixture of protein, mucous and fatty substances, including calcium soaps, constitutes the so-called membrane around the fat globules. By using for the most part physical methods of isolation and purification, except for the fractionation of the final product by solvents, we have secured the following results. When cream was repeatedly diluted with distilled water and recovered by centrifugal separation until the washings no longer give a Fehlings and biuret test, the cream was still a highly stable emulsion. This cream, however, readily formed butter on churning, the buttermilk from which had the appearance of dilute skim milk. A similar fluid was obtained by gently washing the melted butter with warm water until the melted fat rose as a clear liquid. We have assumed that both the buttermilk and butter washings contained the substances which adhered most closely to the surface of the fate globules in the original cream.

The anti-rachitic properties of breast milk.

The cause of rickets in breast-fed babies has not been satisfactorily explained. It is not due to deficient phosphorus or calcium in the milk, as Von Meysenburg, 1 Von Meysenburg and DeBuys 2 have shown that the milk consumed by rachitic infants is no lower in its phosphorus or calcium than that received by normal infants. Courtney, 3 making a similar finding as regards K and Ca, points out that the diets of the mothers were deficient in fresh fruits, vegetables, and milk. Contrary to the finding of Lesné and Vagliano 4 that breast milk does not have anti-rachitic properties we have found that it may be strongly anti-rachitic. While we can not state definitely that the anti-rachitic factor is present in breast milk only, as it is present in the food of the mother, we have found that a diet containing an ample supply of green vegetables, fruits, eggs, and milk, in addition to a small daily dosage of cod-liver oil, the fat of breast milk is markedly anti-rachitic. The milk fat used was obtained from two sources; one a composite fat from the milk of three mothers on the same diet and one a fat from the milk of one mother. The first sample was fed at a level of 15 to 20 per cent of the food intake to three rats with severe rickets. One of the rats refused the fat, the other two took it for three days and on autopsy showed good line tests 5 The second sample was fed to six rachitic rats at levels ranging from 5 to 25 per cent of the food intake. It was found that a fat level of at least 8 per cent was needed to produce a distinct line test.

Antihemorrhagic Vitamin Effect of Honey.

Summary Buckwheat, alfalfa and mixed honeys when fed incorporated in basal ration to vitamin K depleted chicks were found to possess a definite antihemorrhagic activity equal to approximately 0.25 μg of 2-methyl-1,4 naphthoquinone per gram of honey. The antihemorrhagic activity of honey was greatly lowered when honey was administered in an aqueous solution directly to the vitamin K depleted chicks. It was demonstrated that the antihemorrhagic activity of 2 -methyl-1,4 naphthoquinone is reduced about 3 times when fed in aqueous suspension. The antihemorrhagic activity of alfalfa hay in water suspension was practically nil while with an addition of 2 drops ethyl laurate, the prothrombin time was quite satisfactory.

Anthocyanin and flavone-like pigments in phytophagous and predaceous forms of Hemiptera.

The identification of carotin as the chief cause of the red and yellow hypodermal colors seen in the predaceous stinkbug Perillus bioculatus (Fab.), reported in the preceding abstract, suggested an examination of the red pigment of other Hemiptera. It was found that red pigment in phytophagous and predaceous families of this order of insects is not limited to one type of substance. Water-soluble pigments appear to be more common than carotin. The aphid (Tritogenaphis rudbeckiae, Fitch) owes its vermilion color chiefly to an anthocyanin-like pigment, although small quantities of carotin also occur in the bug. On the other hand the red color of the red and black patterned phytophagous box-elder plant-bug (Leptocoris trivitatus, Say), the milk-weed plant-bug (Lygaeus kalmii, Stal), the bladder-nut plant-bug (Lopidea staphyleae sanguinea, Kngt.), the maple plant-bug (Coccobaphes sanguinareus, Uhler), and the predaceous Assassin-bug (Eulyes illustris, Stal) is due to a flavone-like pigment.

Carotin in Perillus bioculatus (Fab.) and its derivation from the lymph of Leptinotarsa decemlineata (Say).

One of us 1 has shown that the variations in the hypodermal color pattern of the stink-bug Perillus bioculatus (Fab.) from white and black to red and black (with various intermediate yellow and black forms) are not caused by inheritance but by variations in physiological activity, which can be controlled by the temperature of the environment, and influenced by sexual functions, such as egg laying. The food of the stinkbug is always highly colored with orange-yellow pigment for it consists almost exclusively of the eggs and larvae of the potato beetle, Leptinotarsa decemlineata (Say), as well as the adult beetle itself. When the larvae and adult beetles are attacked the golden yellow lymph is the only portion eaten. A chemical examination of the pigment in the lymph of the potato beetle showed that it consists exclusively of carotin. No other carotinoids could be detected. The concentration of carotin in fresh lymph obtained from 200 full-grown larvae was found to be 0.0136 per cent, which is as high as is encountered in fresh green leaves. The red and yellow colors in the hypodermis of the stink-bug were also found to be due to carotin. Some water-soluble substance yielding yellow solutions was also present in the hypodermis, but it is doubtful whether it contributed greatly to the color pattern.