Turning Eggs.
The subject of turning eggs is another source of rather meaningless controversy. Of course, the hen moves her eggs around and in doing so turns them. Doubtless the reader, were he setting on a pile of door knobs as big as his head, would do the same thing. As proof that eggs need turning, we are referred to the fact that yolks stick to the shell if the eggs are not turned. I have candled thousands of eggs and have yet to see a yolk stuck to the shell unless the egg contained foreign organism or was several months old. However, I have seen hundreds of blood rings stuck to the shell. Whether the chick died because the blood rings stuck or whether the blood rings stuck because the chicken died I know not, but I have a strong presumption that the latter explanation is correct, for I see no reason if the live blood ring was in the habit of sticking to the shell, why this would not occur in a few hours as well as in a few days.
In the year 1901 I saw plenty of chicks hatched out in Kansas in egg cases, kitchen cupboards and other places where regular turning was entirely overlooked.
Mr. J.P. Collins, head of the Produce Department of Swift & Co., says that he was one time cruelly deserted in a Pullman smoker for telling the same story. The statement is true, however, in spite of Mr. Collins' unpleasant experience. Texas egg dealers frequently find hatched chickens in cases of eggs.
Upon the subject of turning eggs the writer will admit that he is doing what poultry writers as a class do on a great many occasions, i.e.: expressing an opinion rather than giving the proven facts. In incubation practice it is highly desirable to change the position of eggs so that unevenness in temperature and evaporation will be balanced. When doing this it is easier to turn the eggs than not to turn them, and for this reason the writer has never gone to the trouble of thoroughly investigating the matter. But it has been abundantly proven that any particular pains in egg turning is a waste of time.
Cooling Eggs.
The belief in the necessity of cooling eggs undoubtedly arose from the effort to follow closely and blindly in the footsteps of the hen. With this idea in mind the fact that the hen cooled her eggs occasionally led us to discover a theory which proved such cooling to be necessary. A more reasonable theory is that the hen cools the eggs from necessity, not from choice. In some species of birds the male relieves the female while the latter goes foraging.
But there is no need to argue the question. Eggs will hatch if cooled according to custom, but that they will hatch as well or better without the cooling is abundantly proven by the results in Egyptian incubators where no cooling whatever is practiced.
Searching for the "Open Sesame" of Incubation.
The experiment station workers have, the last few years, gone a hunting for the weak spot in artificial incubation. Some reference to this work has already been made in the sections on moisture and ventilation. Before leaving the subject I want to refer to two more efforts to find this key to the mystery of incubation and in the one case at least correct an erroneous impression that has been given out.