 Shapiro had been Hogben's student in Cape Town, and he acknowledged that Hogben had suggested that Xenopus was a suitable subject for general research.The pregnancy test itself was discovered by Shapiro and his co-researcher, Harry Zwarenstein, and their results and report had been widely published in medical journals and text books in South Africa and the United Kingdom; in their report published by Royal Society of South Africa in October 1933, Shapiro and Zwarenstein announced that in the previous month they had successfully used Xenopus in 35 pregnancy tests.The following spring "Nature" carried their report.