In 1854 he began to study for the Presbyterian Ministry at New College, Edinburgh, but then decided to specialise in natural sciences.

[5] He oversaw the transfer of the British Museum botany collections from Bloomsbury to South Kensington, and saw off an attempt to have them moved to Kew.

[10] In his 1876 presidential address[11] to the Geologist's Association he argued that "the facts of palaeontological botany are opposed to evolution".

This lecture was widely publicised and may have contributed to Darwin terming the origin of the higher plants an "abominable mystery" in 1879.

His administrative records from his role as keeper of the Botanical Department are held at the Natural History Museum Library and Archives.

[15] A series of Carruthers' notes and illustrations are held at the Cadbury Research Library, University of Birmingham.