I made last week an interesting discovery for my frog stamp collection : a stamp that pictures a stamp that pictures a frog ! Here are the details.
This stamp was issued in 1976 by Netherlands. It belongs to a set of stamps that were all issued with surtax for various purposes. The surtax of this specific stamp was used to help wildlife protection.
The stamp pictures a Green frog (Rana esculenta). The design of the stamp is not very exceptional, but this is one of the very rare stamps that picture frog eggs. I only know another stamp from Spain, picturing a Bell toad (Alytes obstetricans) with eggs. So in itself this stamp was quite interesting.
In 1979, the theme of Europa stamps was the postal service. At this occasion, Netherlands has issued two stamps among which one celebrates philately : here is the stamp.
As you see, the stamp pictures a magnifying glass, and a set of stamps issued by Netherlands. And among the stamps that you see, there is the frog stamp of 1976 (on the right side). So this Europa stamp can fit in my collection because it pictures a frog !
Actually it pictures a stamp that pictures a frog ! A frog on stamp on stamp. I think this is the only existing case!