Experiment Station Record, Volume 92, January-June, 1945 Page: 37
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1945] GENETICS 37
Effect of testosterone propionate on thermo-regulatory function of rat
scrotum, J. O. ALMQUIST and F. N. ANDREWS. (Ind. Expt. Sta.). (Anat. Rec.,
89 (1944), No. 2, pp. 125-133).--Evidence is presented that the thermoregulatory
function of the rat scrotum is dependent on the testicular hormone. Scrotal contractility
in the rat was decreased or prevented by castration, and was measured,
and the weights of the scrotum and seminal vesicles were recorded in 100 rats
following castration and injection with testosterone for 7, 14, and 21 days and
compared with controls at 90 and 111 days. The results were analyzed by variance.
The histological changes in the pituitary caused by estrogen, I. T. ZECKWER
(Science, 100 (1944), No. 2589, p. 123).--Attention is called to the similarity
between the cytological. changes in the pituitary due to pregnancy and those; caused
by estrogen administration. The explanation given is based on the high estrogen
production of the placenta. "It seems reasonable to ascribe the histological changes
to hypersecretion of the pituitary factor stimulating the mammary gland during
the period when the breast is undergoing hyperplasia preliminary to lactation and
to secretion of lactogen when the final period of pregnancy is reached."
Relative productivity under different systems of mink matings, C. F. BASSETT,
F. WILKE, and 0. P. PEARSON (Amler. Fur Breeder, 16 (1944), No. 11, pp. 16-22,
illus. 2).-Results of the mating of 450 mink females indicated that the litters
averaged 4.11 kits each from those mated on 2 consecutive days and subsequently
remated, as contrasted with 4.08 kits from females mated on 2 consecutive days
only. Among 187 mated once, there were produced 3.54 kits per litter. It is concluded
that there is definite increase in size of litter produced by matings on 2
consecutive days. These results were separated by adult and yearling females,
which showed the same conclusions.
A further note on size differentiation in Single Comb White Leghorns, I. M.
LERNER and C. A. GUNNS. (Univ. Calif.). (Poultry Sci., 23 (1944), No. 4, pp.
349-351).-Further study of the size differences in two lines of White Leghorns
(E. S. R., 90, p. 468) revealed that postembryonic growth differences were mainly
responsible for the observed dissimilarity in shank lengths. Differences between
them in the growing period were mainly ruled out, but there may have been differences
in the original shank length. From 5 to 13 embryos were removed' each day
of incubation from both lines. The production-line embryos were, with one exception,
heavier than the size-line embryos, and, with a similar exception, had longer
shanks at each age. The higher growth rate of the production line may be due to
difference in egg size and also in embryonic mortality. Initial size differences were
not involved in the differentiation between the two lines.
Interbreed transplantation of definitive papillae as a means of analyzing
feather pigmentation in fowl, H. WANG (JoZsr. Expt. Zool., 96 (1944), No. 1,
pp. 103-127, illus. 14).-Transplantation experiments were conducted involving the
whole or portions of the active and resting papillae between the breast and saddle
tracts of the feathers of Brown Leghorns, White Leghorns, and Barred Plymouth
Rocks of both sexes and Brown Leghorn capons. The transplantation experiments
were conducted in three age groups--, 3, and 8-12 mo. "The results of this work
supplement the conclusions of Wang' that the functions of the epidermal and dermal
components' of the feather papilla are, respectively, the full realization of tract
specificities and the control of normal development as well as the determination
of the symmetry of the regenerating feather." An extensive bibliography is included.
The significance of inherited characters affecting egg production, F. A. HAYS.
(Mass. Expt. Sta.). (Poultry Sci., 23 (1944), No. 4, pp. 310-313). -Classification
of 1,220 Rhode Island Red pullets hatched in the 5-yr. period 1938-42 showed an
1Physiol. Zool., 16 (1943), No. 4, pp. 325-350, illus. 23,
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U.S. Department of Agriculture. Agricultural Research Administration. Office of Experiment Stations. Experiment Station Record, Volume 92, January-June, 1945, book, 1947; Washington D.C.. (digital.library.unt.edu/ark:/67531/metadc5064/m1/50/: accessed June 25, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.