water-flea's

Updated: May 21, 2025

It is not surprising, then, that the long course of natural selection and survival of the fittest has resulted in the fixing in the blood and the living cells immediately connected with it of extraordinary protective powers. I have watched them with the microscope at work in transparent minute living water-fleas eating up, and digesting microbes which had got into the water-flea's blood.

Sir E. Ray (Edwin Ray) Lankester - More Science From an Easy Chair