COAT-PATTERN IN MAMMALS 



A Medium of Real Value to the Breeder, Since it Enables Him by Analysis to 



Detect in Many Cases the Genetic Composition of His Animals — 



Mendelism in the Hands of the Fancier. 



Q. I. Simpson, Palmer, Illinois 



COLOR, or coat-pattern, is of 

 little commercial importance 

 on domestic animals destined 

 for pail or plow, while it is 

 entirely lost at skinning if the animal is 

 destined for slaughter. Nevertheless, 

 it has a real value to the fancier as a 

 means of determining the purity of his 

 breed, as well as to afford him a source 

 of scientific entertainment. In the 

 case of most pedigree breeds, pattern 

 and color are an integral part of the 

 standard score-card, and therefore must 

 receive consideration from the breeder 

 who handles pedigreed stock. 



As the origin of most breeds is known, 

 the latencies which they contain are of 

 use to the analyzer. One of the most 

 striking features which can be dealt 

 with in this way is the white belt which 

 is a feature of the colored coat of many 

 mammals. 



It is of relative location regardless of 

 its dimension. In swine its center falls 

 in the shortest line measuring over the 

 shoulders from toe to toe, except in the 

 latent belt of the Red Duroc, which is 

 located farther back. So nearly in the 

 same place is the belt regularly located 

 on all swine, that it must be believed a 

 peculiar cell-localization, belonging in 

 general to all species of Suidae in 

 latent condition. 



W. J. Spillman of the United States 

 Department of Agriculture was perhaps 

 the first to publish a genetic hypothesis 

 regarding the white belt in mammals, 

 basing his opinion on his observations 

 in my own herds of hybrid swine; and 

 it is due to the stimulus received from 

 him that I began to take an interest in 

 this character. We had undertaken by 

 reciprocal crossing of contrasted breeds 

 to decide an important genetic question : 



the potential hereditary value of sex, 

 the potency or hyper-potency of male 

 or female. While this series of experi- 

 ments was in progress, Mendel's Prin- 

 ciples of Heredity were uncovered, add- 

 ing more facts and greater fascination 

 to the work. 



FOUNDING A NEW RACE. 



Among the hybrids on which we were 

 working, we found synthetic belted pigs 

 in the white contingent of the second 

 Tam worth cross on White Yorkshire. 

 Pigs with white hair but clouded skin, 

 Fl, were bred back to pure Red Tam- 

 worth, getting the straight Mendelian 

 ratio of 2:2, whites and reds; but some 

 whites remained white only until they 

 were weaned. Red hairs then began to 

 appear throughout the front and hinder 

 areas, making in different subjects vary- 

 ing degrees of red-roan. Some even 

 gained clean, white belts, located as in 

 the Belted Black Hampshire. Looking 

 back to these various belted red-roans, 

 I now believe that clean red-end Belts 

 could have been selectively evolved by 

 interbreeding the reddest. In that case, 

 my new race of Belted-Reds would have 

 been better founded than by the method 

 which actually produced them — namely, 

 crossing these synthetic belts with the 

 black-end Hampshire ; for with the latter 

 operation I lost time in cleaning away, 

 by elimination, the Hampshire black. 



Belted swine offer the seeming para- 

 dox of explanation by postulating one 

 factor or two factors. An explanation 

 will make this clear. Taking the red 

 Tam worth, or the wild Sus from the 

 Schwarzwald, any addition of the proper 

 potential of unspotting white from a 

 White Yorkshire will produce some clean 

 white belts, with incipient pigment of the 



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