English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The chemical identification of each of the recognized vitamines as individual substances or chemical groups is greatly to be desired. As the result of certain studies1 which I made on the physiological relation between the yellow carotin and xanthophyll pigments of plants and the yellow lipochromes of animal tissues and fluids, I became impressed with the fact that there seemed to be more than a casual relation between the simultaneous presence of the plant carotinoids and fatsoluble vitamine in butter fat and egg yolk and in the leafy parts of green plants, and the simultaneous absence of carotinoids and fatsoluble vitamine from lard. That phase ofmy carotinoid studies showing the physiological identity of egg yolk lipochrome with plant xanthophyll suggested that the fowl should be a suitable animal upon which to test the relation of plant carotinoids to growth and reproduction. It was decided to approach the question by attempting to raise a flock of chickens from hatching to maturity on a ration devoid of carotin and xanthophylls. The problem which was presented was therefore mainly one of selecting a ration devoid of yellow plant pigments but which was presumably adequate otherwise for the normal growth of chickens. Three experiments were undertaken. The first was a preliminary experiment, during the winter of 1916-17, to test the efficacy of a ration of white corn, white corn bran, bleached flour, skim-milk and .582

Growth and Reproduction in Fowls in the Absence of Carotinoids and the Physiological Relation of Yellow Pigmentation to Egg Laying