64 



The Journal of Heredity 



vi'?' A -v^' 



-i,</'-i. r^ 



■iar- •«,*&; 



A SECOND GENERATION BERKSHIRE X DUROC- JERSEY CROSS 



An illustration of the appearance of the Berkshire type of forehead in the second generation. 

 Contrast with the different type shown in the following figure. (Fig. 13.) 



single factor which alone produces 

 black spots irregularly scattered over 

 a lighter ground color and, when ex- 

 tended by the action of \arious modi- 

 fying factors, it covers all the body 

 except the "six white points." 

 Reasoning from the similarity in 

 appearance and ancestry rather than 

 from any definite experiinental data, 

 the Spotted Poland-China possesses 

 the same fundamental factor for 

 black si)ots but many of the factors 

 which inHuence the size of those 

 spots are absent. 



Red: Two kinds of self red are geneti- 

 cally distinguishable 1)\- their be- 

 havior toward self white. Possibly 

 the factors which affect the white 

 are distinct from the factors ft)r red. 

 DilTerences in the intensity of the red 

 seem tf) be inherited but there are no 

 ex|)erimental data to back up thai 

 I)oi)ular f)pini«)n. 



Roanin]!^: Appears (juite fre(|uentl\- 

 among the descendants of self whites 



by self reds, or of self whites by 

 belted blacks. Often it is not appar- 

 ent at birth but develops later. 

 Immature Striping and Adult Agouti 

 of the Wildllog: This pattern is domi- 

 nant over all other co'ors except self 

 white and the white belt, but the 

 dominance is not always complete. 



COLOR RESULTS FROM THIS EXPERIMENT 



The European wild hog is of a color 

 corresponding very closeh- to the agouti 

 or graN- jxittern common among many 

 other wild mammals, except that in this 

 case it is an uncommonK- dark slaty 

 shade. Another interesting feature is 

 that the young are born with longitu- 

 dinal stripes about a centimeter wide 

 running the full length of their bodies 

 and extending over all the back 

 and sides, but with very light bellies. 

 This is (juite evidently a |)rotective 

 coloration for at a short distance they 

 blend in \i'r>- well with the sticks and 

 trash on the ground. The contrasting 



