The first editions of the two titles in Jenk’s Talking Animal Series (1901, 1902) can be hard to distinguish from the later editions that were published in Series 125 The Little Men and Women Series starting in 1907. There are several points that distinguish the earlier from the later books.

Galopoff, The Talking Pony was first published in 1901.
The first edition (1901):
1. Pictorial endpapers
2. Glossy frontispiece and illustrations
3. Title page with some red lettering and lines

Second Edition (1902)
1. Endpapers are now plain
2. Glossy frontispiece and illustrations
3. Title page with some red lettering and lines

Gypsy, the Talking Dog (1902)
First edition:
1. Plain Endpapers
2. Glossy frontispiece and illustrations
3. Title page with some red lettering and lines

Editions in the Little Men and Women Series (1907 and later)
1. Plain endpapers
2. All of the pages in these books are on plain paper. No glossy pages.