I still havent figured out the meaning of this as to my knowledge no one else has either. I do have an idea that may not be correct but it sounds good.
The origin of the word yankee it's self I am not sure but if interpreted as the new people's of America, the new revoulution and people of this revolution. YANKEE as the people of a revolution. And the word ROSE as the symbolism of its color. The color of blood, maby even its symbolism of love.
Could this posibly be his desire for his new religion to live in the blood of America, as a new revolution. For his ideas to be a revolution in the blood. Blood being the revealing factor of the fact that we too are animals.
I don't know, it just came to mind and seemed to make a little sense. Just something to ponder. Enjoy and reply your thoughts. Your ridicule and disagreement are anxiously awaited.