For this reason he regards them as Gregarines rather than Coccidia.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 5" by Various
These exceedingly small germ-cells afterwards develop into the very different, adult gregarine-cells.
"The Biological Problem of To-day" by Oscar Hertwig
F. Redi (1684) is said to have been the first to observe a Gregarine parasite, but his claim to this honour is by no means certain.
"Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 5" by Various