"This video is taken from a 16-mm movie made in the 1950s by the late David Rogers at Vanderbilt University... It depicts a human polymorphonuclear leukocyte (neutrophil) [a type of white blood cell] on a blood film, crawling among red blood cells... The neutrophil is 'chasing' Staphylococcus aureus microorganisms, added to the film." ([Source](https://goopenva.org/authoring/459-white-blood-cell-chases-bacteria/view))