The use of the male California toad in the diagnosis of pregnancy.

The California male toad, readily available in most areas of the state, and for many other reasons a better subject for test purposes than the frog, was used in 237 tests to determine the presence or absence of pregnancy in humans. Human urine was injected into the toads, and the cloacal discharge then was examined for the presence of sperm. There were only two false reactions in the series-both false negative. In subsequent tests in both these cases, the result was positive.