124 



THE AMEBIC AN NATURALIST [Vol. LTIT 



The Cr factor has been described in some detail be- 

 cause it plays an important part in the production 

 of the synthetic pink-eyed self whites. G and Ca 

 are dominant to Cr, while it in turn is dominant to 



Ca. 



Ca, albinism. Albino guinea-pigs generally tend to have 

 some pigmentation on the nose, ears and feet. 

 This varies in amount depending on the other fac- 

 tors present. A he albino is almost if not quite 

 devoid of pigment (J* 1830.1, Fig. 1), while a BE 

 ' albino is heavily pigmented at its extremities 

 ($1866.2, Fig. 1). In all cases, however, the eyes 

 are pink and the greater part of the coat is white. 



P, dark-eyed. 



p, pink-eyed. The eyes are as pink as those found in 

 albinos. Black (B) or chocolate (h) are also af- 

 fected, becoming quite dilute, while red is unaf- 

 fected. 



It will be seen from the description of the factors 

 given aliove tliat if we can o])taiii an animal which is a 

 non-('xt(Mi(l('(l ii()ii->('ll()\\-, cCr, juid tlierofoi-e a self white, 

 and wlii.-h iii Mildltlnii 1^ or pink .'vod. we -hall have a 

 pink-('\c(l scir while ( (■('>)>). which is not an albino in the 

 ordinary sense of tlie word as ap[)lied to guinea-pigs, 

 but which nevertheless to all appearances in an albino 

 (see $1118.1, Fig. 1). There is one difference, however. 

 Albinos vary considerably in the amount of pigment in 

 the ears, nose and feet depending on whether E, e'^, or B 

 are present or absent. The sviithetic pink-eyed self 

 wliites 071 the other h[md cannot carry E or e'', but may 

 carry //. The ]>ink-('yo(] fjictor (/>) dilntt^s bhick pig- 

 ment { /!) to such ;in rxK'iit that it is ini})ossi1)le to tell 

 by th.. ;ippc;ir;i!ic- of ih.- .•inim.-il wli.'th.T oi" not black is 

 ))r('.s,.iit. All thr >> mil. 'tic pink-ex rd -elf whites arc 

 thei-cfoi-o ;i jturc whit*' .'uid fnllil the uninca pig fancier's 



