Growth of Chicken-Embryos. Das Wachstum des Hühnerembryos in Abhängigkeit von verschiedenen Temperaturen und Feuchtigkeitsgraden im Brutapparat. N. M. Schkljar. Archiv für Geflügelkunde, 1935, No. 5.

Summary:

1. 1. A completely regular and strong growth of the hen embryos is obtained with a temperature of 38.4° C. (101.1° F.) and 64% moisture.

2. 2. A temperature of 39.9° C. (103.82° F.) and 62% moisture have a somewhat depressing effect on the developement of the embryos during the first six and last two days of the incubation, an increase in growth taking place on the 16th days.

3. 3. A high degree of moisture of 77% and a temperature of 38.3 ° C. (100.9° F.) prevent growth up to the 18th day, a decisive increase taking place after this date.

4. 4. With a low temperature of 37° C. (98.66° F.) and a moisture content of 63%, the developement of embryos remains noticeably backward, specially during the first few days. Under such conditions, as early as after the sixth day, growth in relation to the control group is delayed by two days.

5. 5. Between the increase in weigth and the developement of embryos, there exists, in an early stage, an inverted ratio of dependance.

6. 6. The rate of growth of the internal organs is not a process working within itself, but subject to the general conformity to law.

7. 7. The growth of the embryo is not the result of an uninterruped developement, but consists of a sequence of increases and depressions.

Vitamin A determination, Relation between the biological, chemical, and physical methods of test. K. C. Lathbury. Biochem. Jour., Vol. 28, 1934, p. 2254.

This investigation, conducted in the Physiological Laboratories of The British Drug Houses, Ltd., was undertaken because of doubt cast by some investigators, notaby Coward et al, on the value of the Carr-Price color test, which is used by the British Drug Houses in describing the potency of their products. Six samples of crude liver oils or concentrates and a sample of the international standard were compared for their content of vitamin A by feeding experiments on rats, the Carr-Price test, and the spectrophotometric test.

Effects of different Brooding temperatures on Pullorum Disease. W. L. Mallmann. Vet. Med., Vol. 29, 1934, p. 254.

The author found the loss of chicks from pullorum disease in infected and mixed lots to be six or seven times as high in chicks brooded at 72° F. as in those brooded at 96°. The transmission of the disease from the infected to the uninfected stock was much higher at the unfavorable temperatures of brooding. The information obtained is considered to emphasize the extent to which unfavorable conditions lower the vitality of chicks and render them more susceptible to pullorum disease.