Browsing recently on Ebay, I serendipitously discovered this book. Immediately, I recognized it as a possible Morse design and I started to look closely for a signature. Fortunately there was one, signed A. M., embedded in the title panel in the lower left corner and you can see a detail of it below, In Honour's Cause is a children's book and looks very much like the cover published a year later for The Missing Prince (Dodd Mead, 1897; Dubansky entry 97-3). It is the second book found for a work by Fenn; the other being First in the Field, posted two entries ago. There are very few pictorial covers designed by Morse and these are logically found on books of children's literature. What stands out to me about their design is the wiggly (for lack of a better word) character of her drawing, the way she blocks out form and also the lettering style. If you look at enough of her designs, you will recognize them as well.
George Manville Fenn
In Honor's Cause. A Tale of the Days of George the First.
Illustrations by Lancelot Speed
New York: Dodd, Mead and Company, 1896
Burr Printing House, New York
202 x 140 x 30 mm
Buy a copy of The Proper Decoration of Book Covers: The Life and Work of Alice C. Morse