Name that book: A survey of Heraldry (non-fiction, ca. 1970)

Read in about 1970, but almost certainly older than that, perhaps as much as 50 years older. The only feature I can remember now that would distinguish it from any other survey of heraldry is the chapter on marks of cadency. This featured an imaginary conversation among three brothers as they hashed out how they might apply cadency to their arms.

Cross-posted to Name that Book and Heraldry