Note 61 — Chapter XII · INHERITANCE.
Reading edition
The Mot-mot habitually bites the barbs off the middle part of the two central tail-feathers, and as the barbs are congenitally somewhat reduced on the same part of these feathers, it seems extremely probable, as Mr. Salvin remarks (‘Proc. Zoolog. Soc.’ 1873, p. 429), that this is due to the inherited effects of long-continued mutilation.