A. J. MACDONALD & T. S. KRISHNAN 319
of eggs from different individuals but that the quality of the eggs from the same
individual remained relatively constant. These findings have been corro-
borated by later workers [Lorenz, Taylor and Almquist 1934 ; Almquist and
Lorenz 1935 ; Knox and Godfrey 1934, 1938 ; Van Wagenen and Hall 1936 ;
Van Wagenen, Hall and Wilgus 1936 ; Winton 1937 ; Munro 1938].
The statement of Jull and Byerly [1934] that the eggs of pullets in the early
stage of production have a higher percentage of thick white than those laid
at a later date was refuted by Lorenz and Almquist [1936]. Lorenz, Taylor
and Almquist [1934] found that the quality of the white was largely determined
by inheritance, but rather limited data by Van Wagenen and Hall [1936] sug-
gested that there was little relationship, as regards the percentage of thick
white, between the eggs of a pullet and those of her sire's dam. Knox and
Godfrey [1940] have shown that it is possible to breed two lines of fowls, one
laying eggs with a high percentage of firm albumen and the other a low percent-
age. Knox and Godfrey [1934] concluded that White Leghorn eggs had a
significantly higher percentage of thick white than Rhode Island Red eggs but
Van Wagenen, Hall and Wilgus [1937] found no appreciable differences in the
firm albumen content of eggs from the common commercial breeds.
Lorenz and Almquist [1936], on housing birds at temperatures of 60°F.
and 85°F. and examining the eggs within 15 minutes of production, found no
significant correlation between the housing temperature and the percentage of
thick white. In another experiment, the birds were kept under identical con-
ditions, the eggs were collected within 15 minutes of laying and were then
stored overnight at temperatures of 40°F. and 86°F. respectively. As the eggs
stored at the higher temperature had a lower percentage of thick albumen than
those stored at a lower temperature, it was concluded that high storage tem-
perature, even for relatively short periods, lowered the percentage of thick
white and that the seasonal variations noticed by other workers were mainly
due to variations in the storage conditions subsequent to production. Hunter,
Van Wagenen and Hall [1936] and Knox and Godfrey [1938], on analysing
eggs within a few hours of production, found that winter eggs had a higher
percentage of thick white than those produced in summer and attributed the
change to seasonal effects. Ringrose and Morgan [1939] also found a seasonal
variation in quality, even though the eggs were stored overnight in a cool base-
ment, but unfortunately no temperature records were kept. Wilhelm and
Heiman [1938] trapnested birds 6-7 times daily and transferred the eggs as
quickly as possible to an egg humidor, maintained at a temperature of 40-60°F.
and a relative humidity of 78-85 per cent. The eggs were examined for quality
on the day after production and it was found that there was a falling-off in the
percentage of thick white from April to July but that quality improved as the
weather again grew cooler.
From the above brief review of the literature on the subject, it is apparent
that the whole question of the quality of eggs when new laid requires further
investigation. Though at first sight the literature appears somewhat in-
conclusive it does show that many of the apparent discrepancies are due to the
varying conditions under which the experiments were carried out. It also
shows the value of working under controlled conditions and the necessity of
reporting all possible data.