LINNEAN SOCIETY OF LONDON. 21 



PRESIDENTIAL ADDRESS, 1916. 



The Hereditary Transmission of Small Variations 

 AND THE Origin of Butterfly Mimicry. 



Contents. 



Page 



A. Introduction 22 



B. Indirect and Direct Evidence of the Hereditary Transmission op 



Small Variations 23 



a. Persistent Variation in two Colonies of a Zygwnid Moth on 



E. Dartmoor. 



b. Hercditarj/ Transmission cf Small Variations in the British Moth 



Spilosoma niendica. 



c. Hereditary Transmission of Small Variations in the European 



Moth Sjntoniis pliegea. 



C. Geographical Eaces OR Sudspecies 26 



I. Direct Evidence of Hereditary Transmission of Local Difference... 27 



a. Local European and British Races of the Butterfly Pieris napi 



hrcd in the London District. 



b. Local British Races of the Moth Aplecta nebulosa hrcd in the 



London, District. 



c. Hereditary Transmission of Small Variations in W. African 



Butterflies of the Genus Hypoliiimas. 



d. Ho-cditary Transmission of Small Variations in theHi\)])Ocoon 



Female of the African Papilio dardanus. 



II. Indirect Evidence of Hereditary Transmission of Local 



Difference 3° 



a. The V-Mark on the Hind Wing of the Danaine Genus 



Tirinnala. 



b. Geoc/raphical Changes in Mimetic S2}ecies corrcsj^onding with a 



Cha nge of Model. 



c. The Mimetic Females of the African Cb.araxes etbeocles. 



d. A Soitth American Heiicoiiius Mimetic of another Species of 



the same Genus. 



D. The Origin OF A Mimetic Pattern 35 



a. A Mimetic Pattern supposed to arise suddenly fmn a set of Factors 



similar to those tchick produced the laitern in the Model. 



b. TJie Edges of Markings in the Patto-ns of Models and their Mimics. 



c. Modes of Occurrence of Dyskgnic Patterns in Butterflies. 



E. Female Mimicry 39 



F. Polymorphic Mimics and the Origin of Mimicry 41 



a. Polymorphic Forms, — Mimetic Const<inf and Non-Mimetic Variahlc. 

 — in the Same Species. 



