Tree shapes

Does anyone else remember the beautiful book "The Butterfly Ball" by Alan Aldridge and William Plomer? I had this book as a child and it was a source of almost endless enjoyment. One of my favourite pictures was of a tree like this, in which shapes were hidden (fish I think). Every page of the book had some kind of mystery or obscured detail within it; a sort of predecessor to Kit Williams' Masquerade in 1979 but without the actual treasure at the end. Talking of which, the story of what happened to the treasure which the clues in Masquerade led to is a fascinating and unpredictable weird one, and can be found here.