THE CONCLUSIONS WHICH WE DERIVE FROM OUR OBSERVATIONS ARE AS FOLLOWS: 1. The excretion of injected, egg-albumen as such is in no case complete. The quantity retained varies from 23 to 100%. 2. The amount retained varies: a) directly with the slowness of absorption. This is determined by the manner of administration. b) directly with the time during which the proteid remains in the body; and the...

Normal chick embryos swallow and utilize the albumen in the egg between the 11th and 15th day of incubation (Witschi, 1949). They use approximately two-thirds of the yolk by the end of incubation (Romanoff & Romanoff, 1949). Thus the embryo has access to 4 g of protein in the albumen and 3 g of protein in the yolk (Romanoff & Romanoff, 1949). Embryos which have been hypophysectomized by partial...

avian leukosis viruses (alvs) cause different types of tumours in poultry and can affect the health and egg production of the birds. to investigate the presence of the virus in chicken layer flocks in shiraz, 222 egg albumen from local layer breeder (25 eggs), local layer grand parent (30 eggs), broiler breeder (60 eggs), commercial layer (46 eggs) and broiler grand parent (61 eggs) were tested...

in the egg shells when the eggs were studied in UV-light (Fig. 1). Control eggs did not fluoresce. The concentration of oxytetracycline in the egg shell, albumen, and yolk was measured by UV-absorption spectrofluorometry (Hayes and DuBuy, 1964). Oxytetracycline was deposited mainly in the shell (0.182 ± 0.028 iig./gm., mean ± SD), and albumen (0.190 ± 0.030 !*g./gm.) whereas the yolk contained ...

Phenotypic plasticity and phenotypic stability are major components of the adaptive evolution of organisms to environmental variation. The invariant two-egg clutch size of Eudyptes penguins has recently been proposed to be a unique example of a maladaptive phenotypic stability, while their egg mass is a plastic trait. We tested whether this phenotypic plasticity during reproduction might result...