CD gives his definition of "highness" and "lowness" as "morphological differentiation" from a common embryo or archetype. JDH’s view, with which CD agrees when it can be applied, is the same as Milne-Edwards’, i.e., the physiological division of labour. There is little agreement among zoologists and CD admits his own lack of clarity.

Is unequal to taking chair as President of Natural History Section of BAAS meeting in Liverpool. Very little fatigue or excitement brings on swimming of head, nausea, and other symptoms.