two trophozoites of Gregarina polymorpha from the gut of the mealworm, Tenebrio molitor. This photo, stained with basic fuchsin, shows the  initial engagement of the primite (to the right) and the satellite (to the left).  The anterior protomerite of the satellite will eventually indent into the posterior end of the deutomerite of the primite. At that point, genetic material will be exchanged.  1000x.