T. S. KRISHNAN 131
TABLE III
Record of weekly average maximum temperature
and relative humidity during the linseed oil
servation experimen
Period of storage
1st week . . .
2nd „ . . .
3rd „ . . .
4th „ . . .
5th „ . . .
Average max.
temperature
°F.
88
86
87
84
86
Av. relative
humidity
per cent
72
75
78
79
76
It, therefore, appears that oil treatment is
unable to check early embryo growth if the tem-
perature is sufficiently high. The average maxi-
mum temperature remained at about 86°F. and
relative humidity round about 76 per cent during
the duration of this experiment. These figures
are more or less similar to those recorded in the
other trials outlined above.
Changes in the interior quality of eggs treated
with raw linseed oil and measured at weekly
intervals are given in Table IV. These figures
relate only to the behaviour of infertile eggs,
since all fertile ones were spoilt before the end of
the first week of storage. From this table it may
be seen that, while the controls decreased by 43.9
per cent from the initial quality in the first week,
the oil-treated eggs showed a drop of only 14.9
per cent during this period. The losses in quality
sustained by control eggs during two and three
weeks of storage were 56.4 and 63.1 per cent
respectively, while those which had been preserved
declined by only 22.7 and 32.5 per cent in the
corresponding periods. During the last two weeks,
the quality remained practically unaffected both
among the control and the preserved eggs. As
judged by the yolk index figures, the rate of
deterioration in the eggs preserved with raw
linseed oil was markedly lower than in the control
eggs and at five weeks the preserved eggs had a
slightly higher yolk index than that of the un-
preserved eggs at one week.
TABLE IV
Changes in interior quality of eggs preserved with
raw linseed oil
Period of storage
Initial . .
1 week . .
2 weeks . .
3 „ . .
4 „ . .
5
„
.
.
Control
Yolk
index
0.415
0.233
0.181
0.153
0.154
0.155
Air cell
depth
mm.
3.0
5.6
7.7
8.6
9.4
10.9
Preserved
Yolk
index
0.415
0.353
0.321
0.280
0.277
0.271
Air cell
depth
mm.
3.0
3.4
4.1
5.1
5.1
5.3
In this experiment the depth of the air cells of
the eggs were also measured whenever quality
determinations were made. The air cells were cut
out with the shell and the depth measured by
means of a spherometer (Plate X, fig. 3).
The increase in the depth of air cells among the
controls proceeded at a much faster pace than
among the preserved eggs. While in the first
week the depth increased by 2.6 mm. in the
controls, the corresponding rise in the oil-treated
eggs was only 0.4 mm. At the end of five weeks,
while the controls showed an average depth of
10.9 mm. in their air cells, those of the preserved
eggs measured only 5.3 mm., which is slightly
less than half of the former. Since the other
conditions of storage were identical, it appears
that oil treatment serves to reduce the rate of
shrinkage. As the relative humidity during the
period of this study was fairly high (76 per cent
on an average), the evaporation suffered by the
untreated eggs would be comparatively less than
they would have experienced had the weather
been drier. It would, therefore, appear that
during the dry summer months, oil treatment
should be even more efficient in reducing the
evaporation of egg contents.
From the progressive changes in internal quality
discussed above, it is apparent that linseed oil is
of material value in conserving the interior quality
of infertile eggs.
CONCLUSIONS
A consideration of the data presented in this
paper warrants the conclusion that green neem
leaves, green shisham leaves, rice husk, dry salt
and wood charcoal are of no appreciable value in