div class=ts-pagebuttonPage 1button div class=ts-image amp-img class=ts-thumb alt=Page 1: Dr R G S Hudson src=https:reader031vdocumentsinreader031viewer2022020212575067df1a28ab0f07ad8973html5thumbnails1jpg width=142 height=106 layout=responsive amp-img divp©1939 Nature Publishing Grouppdiv