Vererbung, Variation, Mutation. 261 



The data on wliich tlie paper is based are records obtained from breeders of 

 nearly 500 kittens from various matings of orange, tortoise-shell and black. 



Doncaster, Cambridge. 



810) Eii'loff, J. 31., Color Factors in the Hair of the Horse. In: Amer. 

 Breeders Mag., Vol. IV, Nr. 1, S. 27— 31, 1913. 



The writer finds (l) that there is one color of pigment running through all 

 colors of hair, (2) that there is an increase in number of pigment granules from 

 the lighter to the darker colors, (3) there is no apparent difference in size in 

 pigment granules, (4) there is no apparent correlation between the size of the 

 medullary layer and the color of the hair with the exception perhaps of the 

 gray (5) and there is a very marked diffei'ence in the distribution of the pigment 

 granules. Seven factors may influence color. 



(a) The pigment factor. This when present in connection with factor b pro- 

 duces color and in its absence typical albino forms result. 



(b) The oxidizing factor. Its effect on the chromogen or pigment factor is 

 uniformily that of color production. In the absence of b typical albinos are formed. 



(cj The clustering factor. This is merely hypothetical, although the Clusters 

 themselves are apparent. 



(^d) The distribution ' factor. The pigment granules in the sorrels sho w a 

 relatively even spacing throughout the cortical layer and the bays show the same 

 conditions between the larger Clusters. The combination of these two factors 

 may show why bay is epistatic to so many other colors. 



(e) The quantitative factor. Increased pigmentation produces darker color 

 effects whether in the presence of factors c or d. 



(f) The pattern factors. These are various according to the patterns that 

 exist in different races. The roan and gray pattern has the greatest influence on 

 the general color effect, (these two are probably almost identical). The amount 

 of white influences mechanically. It is probable that the series in which this 

 factor is present is dominant to the sorrel, chestnut, bay, brown and black series. 



Pearl (Orono). 



820) Bush-Browu, H. K., Horses and Horse Breeding. In: Amer. Breeders 

 Mag., Vol. IV, Nr. 1, S. 21—27, 1913. 



The writer emphasizes the importance of studying the comparative anatomy 

 of the different types of horses. A comparison of the remains of horses from 

 different periods shows that there has been a reduction in the number of lumbar 

 vertebrae and toes as the type has advanced. A number of knees from modern 

 horses, whose type was unknown, showed that the trapezium was present in 

 57 percent of the number examined. A study of the several types of horses 

 would perhaps show that the trapezium is present only in the mongrel horse 

 and may never or rarely be found in the specialized types of trotters. 



Pearl (Orono). 



821) Nabours, E. K., Possibilities for a New Breed of Cattle for the 

 South. In: Amer. Breeders Mag.. Vol. IV, Nr. 1, S. 38—52, 1913. 



Descriptions of the Brahma cattle {Bos indicus) and their distribution are 

 given. They have been introduced into many tropical and subtropical countries 

 and are well adapted to these regions because of their immunity to the destruc- 

 tive tropical cattle diseases. They can also stand severe cold. Cattle raising in 

 southwestern United States was successful during the middle and latter half of 

 the last Century probably because of the presence of Brahman blood in the herds. 



