I have to confess that I don’t remember these, but they would have been around during my childhood. I’d like to think I would have seen some.
While I was pottering in a secondhand and bric-a-brac emporium in Hitchin today I came across this.
Frou jacket
This is a story about Frou the hare, number 4 of Pére Castor’s Wild Animal Books, illustrated by Feodor Stepanovich Rojankovsky also known as Rojan.
There are more examples of his work here http://www.fulltable.com/VTS/aoi/r/roja/r.htm
The series was translated by Rose Fyleman and was published by George Allen & Unwin Ltd in the UK and by Flammarion in France. This book has no date, but Amazon are listing it as 1938.
There’s more on Pére Castor here http://www.answers.com/topic/pere-castor
This book is absolutely enchanting; a mix of non-fiction and a story of Frou the young hare from his early life (His father had been eaten up by a fox and his sister had been carried off by an owl!) to meeting Capucine, his girlfriend and their life together.
We’re introduced to Frou
Frou and Capucine meet
The story covers about a year in their lives. They have to hide from foxes and crows, the huntsmen and their dogs, a separation and a joyful reunion.
The happy ending
The lithographs by Rojan are just gorgeous – I shall be looking for more in the series.
Three Wishes Books 
So pleased to see you found & loved the Pere Castor Frou the Hare. I bought the set of 8 Pere Castor Wild Animals at our local auction (Dukes in Dorchester) yesterday. I can remember almost every page from our nursery 65 years ago. So well worth trying to find the others, such brilliant colours, so fresh.
I have discovered that Lida, the author, was born Lida Durdikova in Prague 1899, married the French publisher Paul Faucher 1933. They created 100s of children’s titles together, Faucher being strongly influenced by the Czech idealist Frantiseck Bakule, who was the 1st Director of the Prague Institute for Disabled children, (after 1914 it focused on rehabilitating wounded soldiers, still exists.)
The illustrations are by Feodor Rojankofsky, a Russian emigre, who went to America when the Germans invaded Paris. He also drew sophisticated erotica! Far too much info you may think… but it makes one realise how lively & creative Paris must have been in those days?
Thanks for your comments. They are beautiful books and I shall certainly be looking out for more.