THE bulk of published work1 on the use of male batrachians as pregnancy test animals has come from the Americas. Early last year, Galli Mainini2 suggested that the test which he initiated using an Argentinian species Bufo arenarum Hensel3 could probably be carried out equally well using an indigenous species, namely, Bufo bufo. A small series of tests was run on Bufo arenarum Hensel. The results4 obtained encouraged us to employ the common toad Bufo bufo.