314; ME. C. C. HURST : EXPERIMENTArj STUDIES 



The Appearance of the Dutch Markings. 



The appearance of tlie true Dutch markings in the second 

 generation o£ the marked line only was as interesting as it 

 was unexpected, especially as there had been no Dutch-marked 

 individual in the ancestry of either the original self-coloured 

 Belgian or the white Angora for at least 8 generations, and 

 probably many more. The fact that these Dutch-marked indi- 

 viduals appeared in about the proportion of one quarter, and 

 bred true at once, was very significant. Erom the Mendelian 

 point of view, the results pointed to the conclusion that No. 3 

 albino Angora gave off gametes carrying the factor for Dutch 

 markings, and that these gametes, uniting with the pure self 

 gametes of No. 4 self-coloured Belgian, gave rise to the slightly 

 marked hybrids of the first generation. Ordinary Mendelian 

 segregation apparently took place in the gametes of these inter- 

 mediate hybrids, giving rise to gametes for self-colour and 

 gametes for Dutch markings in about equal numbers, with the 

 result that in the second generation there were one quarter pure 

 self, one half hybrid marked, and one quarter pui'e Dutch. lu 

 order to test this conception experimentally, a pure self-coloured 

 doe (No. 46) was mated with a pure Dutch buck (No. 51), giving 

 5 young all slightly marked with white, like the marked hybrids 

 of the first generation between the original albino No. 3 and the 

 self-coloured No. 4. 



No. 3 albino was then mated with the same pure Dutch buck 

 (No. 51), giving 11 young, all of which had the true Dutch 

 markings ; showing that this albino was indeed giving off gametes, 

 carrying the factor for Dutch markings ouly. 



The other albino No. 2 (which mated with the self-coloured 

 No. 1 gave the self line) was mated with a pure Dutch-marked 

 doe (No. 52, bred out of the same litter as No. 51), giving 5 

 young, all slightly marked with white, and none with the full 

 Dutch markings ; showing that this a.lbino was giving off gametes 

 carrying the factor for self-colour only. 



The above results go to show that pure-bred albinos carry the 

 latent factors for self-colour and for Dutch markings. 



The extracted albinos were also tested to some extent ; and, so 

 far as the experiments go, it appears that they also carry the' 

 latent factors for self-colour and Dutch markings. 



Thus in the self line, 3 extracted albinos, Nos. 14, 34, and 45, 



