^ßg Vererbung, Variation, Mutation. 



The average for the five years was for the hybrids 50.14 busheis per acre 

 and for the selections 46.09 busheis per acre. The data would seem to indicate 

 that the most promising combinations of hybrids tested are the Bürt crossed 

 with Texas Rust Proof, Burt crossed with Sixty Day, and Sixty Day crossed 

 with Extra Early Burt. The results show the possibilities of improving the oat 

 crop by the selection of good plants from a variety or by the combination 

 through hybridization of the desirable qualities of different varieties and thus 

 obtaining a strain of superior quality. Pearl (Orono). 



379) Castle, W. E., Some Biological Principles of Animal Breeding. 

 In: Amer. Breeders Mag., Vol. III, Nr. 14, S, 270—282, 1912. 



The author briefly reviews Galtons law of ancestral heredity and shows 

 how Mendels law explains the facts of color inheritance more fuUy than Galtons. 

 Mendeüan inheritance is shown in crossing "hooded" rats and Irish rats. 



Pearl (Orono). 



380) Detlefsen, J., The Fertility of Hybrids in a Mammalian Species 

 Gross. In: Amer. Breeders Mag., Vol. III, Nr, 4, S. 261—265, 1912. 



Grosses were made between the wild male Brazilian cavy (Cavia rufescens) 

 and the domesticated female guinea pig (Cavia porcelh(s). The one-half wild 

 hybrids, both males and females were mated back to the original stock. In all, 

 over 1700 hybrids of various blood dilutions have thus been produced. There 

 was found to be a great difference between individual hybrids. One-half of the 

 wild hybrid males had no spermatozoa. The succeeding generations of less in- 

 tense wild males present a consistent series in which a continually increasing 

 percentage of males show spermatozoa. The one-eighth wild males were the first 

 to show motile sperm and were likewise the first to be successfully mated with 

 females. Fertile male hybrids mated with guinea-pig females produce fertile male 

 offspring. The author states that if the cattaloes, mules and other mammalian 

 hybrids are at all comparable to the hybrids in these experiments then fertile 

 races of such hybrids may be produced in the same manner. Pearl (Orono). 



381) Mc Caffrey, F., The lUawarra Breed of Dairy Gattle. In: Amer. 

 Breeders Mag., Vol. IE, Nr. 3, S. 163—173, 1912. 



Valuable herds of Durham, Longhorn, Shorthorn, Hereford, Devon, Holder- 

 ness, Red and Dun Colored Polled and Ayrshire Gattle were started in the 

 virgin country of Illawarra early in the 19*^ Century. Towards the middle of the 

 Century a great Stimulus was given to the dairy business by the fiood of immi- 

 gration. The author for a period of 50 years closely watched the new types of 

 cattle which arose from various crosses of the different breeds. Soil and climate 

 in his opinion have been favorable to the production of a distinct type of dairy 

 animal. The tall, lengthy well-developed cattle of the country were evolved from 

 crosses of the old Longhorned breed with the Shorthorn. Gontemporary with these 

 were to be found in great numbers low-set red dairy cattle evolved from crosses 

 of the Devon and Ayrshire breeds. By mating these two distinct types of cattle 

 has been produced their best strains of dairy cattle. For udder conformation, me- 

 thods of selection were foUowed, and crosses with the best types of the Short- 

 horn and Ayrshire breeds. Pearl (Orono). 



382) Young, C. C, Conceming the Fat-Tail and the Broad-Tail Sheep 

 In: Amer. Breeders Mag., Vol. III, Nr. 3, S. 181—200, 1912. 



