He won the 1942 Duddell Medal and Prize and the 1954 Rumford Medal, the latter 'For his distinguished contributions to the technique for the production of high vacua and to the development of the reflecting microscope'.

When Haeckel was a student in the 1850s he showed great interest in embryology, attending the rather unpopular lectures twice and in his notes sketched the visual aids: textbooks had few illustrations, and large format plates were used to show students how to see the tiny forms under a reflecting microscope, with the translucent tissues seen against a black background.