Abstract
In several expts., animal-free fluid from a Russian clone (Ru 22) of a 5th variety induced clotting and conjugation among animals of the English clone {En 1) of variety VI and clones of all other vars. tested. The fluid from Ru 22 cultures apparently renders the surface of the animals of En 1 sticky so that the ciliates adhere to one another, forming clots and pairs. Clotting and pair-formation among animals of the same mating type differ somewhat from the corresponding activities when diverse mating types are mixed. The Ru 22 fluid also induces nuclear changes in some individuals not associated with others. Other effects noted include darkening, distortion and sluggishness. Only a small % of animals are affected; no effect was observed on animals of some other clones of the same vars.