Two cows are standing next to each other in a field. Daisy says to Dolly, "I was artificially inseminated this morning."
"I don't believe you," says Dolly.
"It's true, no bull!" exclaims Daisy.
Dmitry Iosifovich IvanovskyDied 20 Jun 1920 at age 55 (born 9 Nov 1864).Russian microbiologist who, from his study of mosaic disease in tobacco, first reported the characteristics of the organisms that were later called viruses. (Although he is generally credited as the discoverer of viruses, they were also independently discovered and named by the Dutch botanist M.W. Beijerinck only a few years later.) Ivanovsky had been commissioned in 1890 to study a mysterious disease that was killing tobacco crops in the Crimea. He determined that some agent in sap could transfer disease from plant to plant. Through detailed filtering and microscope work, 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.[Also spelled Dmitri.] |
