312 ME. C. C. HUKST : EXPERIMENTAL STUDIES 



In the third generation 5 o£ the selfs o£ the secoud generation 

 mated together and with 2 pure selfs produced 25 young, all 

 self-coloured. The matinffs were as follows : — 



Table 26. 



Self X Self (F3). 



Matings. Self. Marked. 



S 31 X S 12 3 



S 31 X S 26 3 



S 32 X S 12 5 



S 42 X S 26 4 



S 43 X S 25 10 



Total 25 



In the self-coloured line therefore, with two slight exceptions, 

 the selfs bred true for three generations, including 88 individuals, 

 notwithstanding that all were originally bred from an albino. 



(b) The Marked Line. 



In the first generation all the offspring, except one, were more 

 or [less marked with white on the lore extremities. In the 

 second generation, 4 of the individuals of the first generation 

 bred together produced 67 young, of which 16 were selfs, 34 

 were slightly marked with white like the parents, and 17 had 

 the true Dutch markings. The individual numbers were as 

 follows : — No. 7 gave 5 selfs, 2 marked, and 6 Dutch ; No. 8 

 gave 3 selfs, 9 .marked, and 6 Dutch ; No. 9 gave 8 selfs, 23 

 marked, and 5 Dutch. It will be noted that each individual gave 

 all three kinds ; that No. 7, the self-coloured exception, gave 

 more than the average number of full Dutch-marked and also 

 of selfs ; that No. 9, the one most marked with white, gave less 

 than the average number of Dutch-marked. The individual 

 matings and details of each litter were as follows (S=self- 

 coloured hybrid, M = marked hybrid) : — 



