November 9th
- Russian microbiologist who, from his study of mosaic disease in tobacco, first reported the characteristics of the organisms that were later called viruses.
- Ivanovsky had been commissioned in 1890 to study a mysterious disease that was killing tobacco crops in the Crimea.
- He concluded that some invisible parasite, much smaller than any known bacterium, was the culprit. In fact, his super-small bacterium was a new life form – the virus.
