Thank you.Ok, now I understand the confusion. The "penciled tail" does not refer to the pencilling gene, which is a separate mutation and can only express in BWB birds. The text must be seen in the context of the 1930s, when there was no pencilling (pn) mutation around.
Asmundson was working with dominant and recessive slated birds and the biggest difference is, that rec. slates, other than dom. slated ones, do show a wing and tail pattern.
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