| Description | Slide showing a colour-tinted chart of 'geological age of vertebrate groups'.
There are three colours used - green, blue and red. The green indicates 'predominantly humoral'. Blue indicates 'mixed humoral and nervous'. The red indicates 'predominantly nervous'. The chart's 'X' axis shows the different vertebrate groups 'elasmobranchs', 'teleosts', 'amphibia', 'reptiles'. The 'Y' axis shows geological periods starting with 'Permian', and ending with 'Living'.
Label under slide reads 'Fig. 8. - The geological age of vertebrate groups with different mechanisms for co-ordinating melanophore background responses'.
Below this label, there is an asterisk referring to label on chart which reads 'Pholidophoridae' in the teleosts classification. The asterisk key reads 'seem to be directly ancestral to modern teleosts'. (Zittel, 1938).
White handwritten label above image reads ' Evolution of colour [_]'. |