Considered a scientific dead-end as early as in the 1890s, naturalist linguistics’ top editorial success occurred with the vulgarisation of the biological theory of development. Was the study of the linguistic sphere, “the fourth natural realm”, subordinated for all that to the rather bizarre patronage of Darwinian doctrine ? Nothing has less proven to be the fact. The type of linguistics called “organicist” was producing disciples just as Darwinism, contested on all fronts, was giving rise to passions and denials. Synchronising the two issues, although not erroneous, sheds no light on a number of problems regarding the circularity of the documentary sources on the issues and the field of “naturalist” enquiries thereby homogenised. By dint of interpreting this rising interest as the result of the fashionable sciences cornering the knowledge market, few historians have imagined that the opposite movement might have been going on – to whit that the rise reflects the impact of comparative linguistics on the empirical evidence for the evolutionary hypothesis.