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A. Blomberg, a Swedish scientist, quoted Mendel among the most important investigators in the line of plant hybridization early in 1872 which remained overlooked in literature for many years. Describing dominant and recessive plant characters, Blomberg also touched on the phenomenon of hybrid constancy. For Mendel this was, indeed, the crucial obstacle for the general validity of his theory. Later on it was also the key problem in his experiments with other plant species. Blomberg thus showed that Mendel never accepted the existence of stable plant hybrids, a view which many years later was experimentally confirmed.

THE greatest loss in stored eggs is caused by the effect of bacterial spoilage. The source of this spoilage is usually egg shells polluted by mud and excrements. Pennington (1910) was the first to draw attention to eggs in cold storage with green egg white. There were broken, dirty and washed eggs in the lot. In the microflora of the egg content, bacteria of the genus Pseudomonas were prevalent. This kind of egg spoilage has been termed, after its origin, Pseudomonas spoilage and is the most frequent spoilage in stored eggs. Spoiled eggs emanate different bad smells as sourish, musty, or fruit like. Besides becoming greenish, the egg white liquefies, becomes fibrous and a whitish and later brownish, crusty layer forms on the yolk. According to Bryant and Sharp (1934) bacteria of the genus Pseudomonas penetrate into the egg content through the big pores of the shell. If these pores …

SOMETIMES in the early spring in Czechoslovakia, there is a heavy production of eggs. Egg handling plants are not sure of the best method of preserving surplus eggs, because freezing might influence their interior quality during storage. According to Romanoff and Romanoff (1949) freezing of an egg results in a thinning of the egg white. Moran (1925) reported that freezing at –6°C. resulted in a 42 to 67 percent decrease in thick egg white, with no change in yolk viscosity. Exposing eggs to temperatures below –6°C. resulted in a fatty appearance and increased viscosity in the yolk. The process is irreversible and Romanoff and Romanoff (1949) explained the phenomenon by water freezing out of lecitho-vitelline. At the lower temperature the deterioration penetrates deeper. The freezing point of egg white is –0.45°C., and that of yolk is –0.58°C. In the shell, the egg contents may be cooled to a temperature of . . .

WITH increasing production of eggs, the consumer's demand for quality also increases. In preceding papers (Orel, Musil and Znojilova, 1956Orel, Musil and Znojilova, 1958) it has been shown that the quantity of the dense egg white and the strength of egg shell may be increased, and the rate of evaporation from the eggs may be decreased, by selection of hens according to the quality of their eggs. The quality of egg shells was evaluated by the specific gravity of the fresh laid eggs, a procedure whose repeatability estimates have been stated to be R = 0.33. The breeding quality of the hens, from the standpoint of shell quality, was evaluated by determining the specific gravity of at least ten eggs laid in sequence. Poultry production is dependent on the artificial incubation of eggs. Svensson (1957), studying the relationship of the specific gravity of fresh laid eggs to their hatchability, showed that eggs with …