1 May, 1898.] QUEENSLAND AGRICULTURAL JOURNAL. 867 
Poultry. 
WEAK EMBRYOS IN EGGS. 
Tue complaints last year as to death-in-shell were considerably above the 
average. In some cases the percentage of fertile eggs hatched was lower than 
recorded for several years. On one farm out of 2,500 eggs put down only 
600 chickens were secured. The result was found equally when hens were 
employed as with incubators, and thus objectors to artificial hatching could 
not get hold of any special argument to iilustrate their views. Probably 
fertile eggs were less abundant, but I do not think that the trouble was nearly 
so great in that direction as death-in-shell. 1t is therefore to the latter that 
special attention should be given, in order, if possible, to discover the cause 
thereof. 
‘* ADDLED” EGGS. 
Death-in-shell is the term usually employed when the embryo dies during 
the later stages of development—that is, after it has formed and grown to 
partly fill the shell. An egg in which the germ dies during the first few days 
is called an “addled” egg, though this is hardly a correct term. In this case, 
however, chemical action has taken place more fully and the contents are 
rotten, whereas there has not been time for this change to have taken place 
when the-chick develops beyond the fourteenth day and then dies. The latter 
is even more disappointing to a breeder than the former, for though the result 
in both cases is the same, as. he does not secure that which he had hoped, yet 
it appears worse to lose a bird so near its appearance. 
. : CAUSES. D 
Probably the cause in both cases is pretty much the same, though it need 
not necessarily be so. The embryo during its earlier stages is mach more 
easily killed than the chick. Every variation of temperature is felt more 
rapidly, and has a greater influence upon the former, there being no reserve of | 
heat force, as at a more mature stage. It must not, however, be inferred from, 
this fact that we can treat eggs carelessly at any period, but experience shows 
that they have a considerable amount of natural vigour after the eleventh or 
twelfth day of incubation, and can bear at any rate a fair degree and extent 
of cold. My own impression is that the older an embryo, the less it can stand 
in the way of heat, but observations haye not been made sufficiently upon this 
point to justify decided conclusions. | have found, however, in more than one 
instance that a rise in temperature has done less harm before the tenth day 
than afterwards. But it would not do to accept as authoritative this experi- 
ence without further experiments. At first it was suggested that the albumen 
by which the young embryo is surrounded protects it, but this should be equally 
true in the case of cold. 
We must bear in mind that dealing with animal life is not an exact science, 
and that there are many influences at work which are not understood. It is 
only possible, therefore, to draw conclusions, leaving them to be modified if 
needed by further experience. The following suggestions as to the cause of 
weak embryo in eggs are given in this spirit. 
IS THE MALE BIRD AT FAULT. 
The most natural assumption as to death-in-shell is that the male bird is 
at fault. There are great differences in the natural vigour of fowls, and certain — 
breeds are usually regarded as uncertain breeders after they are two years old, 
more especially the Cochin. But even with more virile fowls the same is true. 
We are not now, however, regarding cases of this kind so much as where the 
