A. J. MACDONALD AND T. S. KRISHNAN 27
of storage, whereas others, held at 113°F., had
ruptured yolks after storage for one week only.
The humidity of the atmosphere also influences
egg quality. Very low humidity leads to rapid
shrinkage, whilst very high humidity encourages
mould growths. Both of these conditions are
greatly accelerated if the temperature is high.
Wilhelm [1939] reviewed the work carried out on
the influence of temperature, humidity and other
factors on egg quality. Kennard and Chamber-
lain [1940] and Klein [1940] showed that, even
when temperatures were low, lack of humidity
resulted in marked loss in grade as judged by
candling. Shoemaker [1936] noted that high
humidity in egg storage was essential for reducing
evaporation and conserving flavour. The ad-
vantages of combining low temperatures with
relatively high humidity in the storage of eggs
have been demonstrated by Jeffrey and Darago
[1940]; Benion and Price [1940]; Kennard and
Chamberlain [1940]; U. S. Egg and Poul. Mag.
[1940] and Snyder [1941].
Fertile eggs also become inedible as a result of
embryo development after a few days' storage in a
warm atmosphere. Rapid spoilage of eggs occurs
in the plains of India owing to the fact that the
temperature is often above the critical tempera-
ture for embryo development; indeed, in the hot
season the temperature often approximates the
optimum for incubation. Though the consump-
tion of eggs in the towns is relatively much higher
than in the villages, production is mainly confined
to rural areas. The quality of the eggs found in
the town markets, especially during the hot weather,
is very poor on account of erratic collection from
the producers, slow transport from the producer
to the consumer and the exposure of the eggs at all
stages to adverse weather conditions. As no
attempt is made to produce infertile eggs at
any season of the year, losses from embryo deve-
lopment during the hot months are excessively
high.
The obvious remedy for the above losses would
be to produce only infertile eggs during the hot
weather and to hold them at low temperatures.
In order to obtain infertile eggs, it would be
necessary either to sell off the males or segregate
them from the females. The latter remedy is,
however, not very practical as production is much
cheaper under free range conditions and it is not
easy to keep the sexes separate in the villages
where this system normally prevails. Further-
more, as the villager firmly believes that hens
will stop laying or give very poor production in
the absence of the male, it would require much
propaganda to overcome the custom of running
males with the females throughout the year. As
proper cold storage conditions are altogether
impractical under present village conditions, it
would be necessary to devise cheap and simple
methods of storing eggs during the hotter seasons
of the year. If such a procedure could be adopted,
many eggs, which at present are a total loss,
could be saved and consumption would be increas-
ed as the eggs would be of a better quality.
Various methods of storing eggs for short
periods, in the absence of ice or mechanical re-
frigeration, have been tried. The Canadian Poult.
Review [1940] quotes Cook as follows: 'In
isolated cases we have found that the mean soil
temperature during the summer months is generally
low enough to suggest that a reasonably satis-
factory storage could be provided in a suitable
cellar with an insulated roof. In other districts
the required low temperature might be obtained by
evaporative cooling, i.e. the evaporation of water
from moss peat, etc., placed around the cooled
space. In other places sufficiently cool spring
water might be available to cool a small holding
room. Few of these methods could be capable of
attaining temperatures of 50°F. but it should be
possible to maintain 60-70°F. in most cases. The
cellar system is useless where ground temperatures
are high; evaporative cooling is useless where the
relative humidity is high and the use of cold
spring water, etc. is limited to the relatively small
number of establishments where it is available'.
Payne [1934] gives the details of construction of
an excellent type of underground cellar and
reports that the inside temperature remained at
70°F. whilst the outside temperature was 100°F.
This type of cellar is, however, too costly for the
small producers and egg retailers normally found
in India. Berley Winton [1933] gives details of
another type which is only partially built into
the earth, but it is unlikely that this system would
prove as efficient. Collopy [1930], Dougherty
[1931], Canad. Poul. Rev. [1940, 2] and Thompson
and Roberts [1940] give details of several types of
coolers based on the spontaneous evaporation
of water. In northern India during the pre-
monsoon months (April to June), the temperature is
high and the humidity low, conditions which are
favourable for cooling the air temperature by
evaporating water.
EXPERIMENTAL
Fig. 1 and (Plate III, fig. 1) give details of a
cooler similar to that described by Collopy [1930].
In order to ensure good aeration, the sides
and bottom of the cabinet and the bottom of
the trays were made of wire netting. Each of the
trays held about 200 eggs. The cabinet gave the
best results when exposed to a through draft in a
shady place.