ABSTRACTS
The Inheritance of Butter-Fat percentage in Crosses of Jersey with Red Danes.—
CHR. WRIEDT. (Journal of Genetics, Vol. 22, No. 1, April 1930.)
In an article, published posthumously under the above title, the author draws attention to the
danger which clearly exists that the occurrence of variations due to living conditions, as well as
others due to non-genetical causes, may be overlooked, and supports the conclusion, which has been
drawn by experienced live-stock breeders, that practically all the economically important characteris-
tics of our domesticated animals depend upon a complicated reaction ; between heritable factors and
the conditions under which the animals live, while there are other variations the causes of which
we do not yet know.
It is well known that precise genetical analysis of heritable factors of economic value in
such slow breeding animals as cattle is extremely slow and expensive and it is obvious that properly
controlled experimentation, on a scale sufficiently large to warrant definite conclusions, presents
obstacles which are practically insuperable. It is, therefore, natural that no great progress has
been made in the analysis of the economically important characteristics of even the principal milk
breeds and clear instances are cited in this article in support of the necessity for accepting non-
genetic variability, which has nothing to do with living conditions. It is pointed out that butter-fat
percentage in milk obviously depends on the fodder to a great extent. Exercise and conditions of
mating of the cows also produce a great deal of variation not influenced by heredity, and the author
states that to this must be added the possibility, perhaps indeed the probability, of other variations,
the causes of which are unknown.
A critical analysis of the heredity of butter-fat, in various crosses between Jersey and Red
Danish cattle, is made in this article, and the following conclusion is drawn, viz.:—
"As a result of the investigations I state as conclusion that all data seem to indicate that one
genetic factor exists which causes the difference in content of butter-fat in the milk of the Jersey
and Red Danish breeds. This genetic factor varies in its effect, but the effect is equally great
whether it meets a gene for high or low percentage butter-fat. Besides this, it is possible that
some of the Jersey bulls used in the experiment had a modifying factor which caused an increase
in butter-fat percentage, but the existence of this factor has not yet been definitely proved." [A. 0.]
Un nouveau medicament pour le traitement des piroplasmoses. (A new drug for
the Treatment of Piroplasmoses.)—A. THEILER. (Bull. Soc. Path. Exot. 1930.
May 14, Vol. 23, No. 5, pp. 506-529. With 22 text-figs.)
The author points out that trypanblue has had a wide application in the successful treatment
of Piroplasmosis both natural and experimental. But, more particularly since the war, there have
appeared on the market substances called trypanblue which not only are devoid of any parasiticidal
action, but are liable on injection even by experienced persons to produce alarming symptoms of
shock. In the course of a tour in Queensland two years ago Theiler heard it said that trypanblue
was quite useless for the treatment of red-water as it occurred in that country.
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