...can you call a farm with a dozen geese a farm? Still, it was a little better for the Jews in Czechoslovakia. There were only two pogroms there. Wh… - Roman Vishniac

I read the first edition of 'Mein Kampf' when it came out in 1923 and even then I knew Hitler meant what he said. I knew the history of anti-Semitism going back for centuries, and I knew all about pogroms in Russia and Eastern Europe. When I grew up and whent to school in Moscow, I experienced anti-Semitism and the restrictions on where Jews could live and work. Hitler systemized anti-Semitism. Pogroms are my business... Oh yes, I could be a professor of anti-Semitism.

My friends assured me that Hitler’s talk was sheer bombast,” Vishniac said in 1955. “But I replied that he would not hesitate to exterminate those people when he got around to it. And who was there to defend them? I knew I could be of little help, but I decided that, as a Jew, it was my duty to my ancestors, who grew up among the very people who were being threatened, to preserve — in pictures, at least — a world that might soon cease to exist.

You can't teach biology with a bottle containing dead animals and organisms.