558 PKOF. E. B. POULTON : NATTJBAL SELECTION 



Natural Selection the Cause of Mimetic Eesemblance and 

 Common Warning Colours. By Edward B. Poulton, 

 M.A., P.R.S., Hope Professor of Zoology in the University 



of Oxford. 



[Bead 17th March, 1898.] 



(Plates 40-44.) 



Contents. 



Page 



1. Historical Introduction 558 



2. The various Hypotheses which have been proposed as Substitutes 



for Natural Selection as the explanation of Mimicry and Common 

 Warning Colours 563 



3. The Relation of the Resemblances under Discussion to other Resem- 



blances in Organic Nature 6(55 



4. Mimetic Resemblance and Common Warning Colours between different 



Arthropod Classes and between various Insect Orders, and their 

 Relation to Similar Resemblances within the Limits of a Single Order 567 



5. Resemblances even within the Limits of an Order are entirely in- 



dependent of Affinity 672 



6. The Resemblances in question are not accompanied by any changes in 



the direction of another Species, except such as assist in the pro- 

 duction or strengthening of a Superficial Likeness 674 



7. Essential Nature of these Resemblances : their Analysis into the 



several kinds of Effect produced 576 



8. Conditions of a Species in any Locality are. chiefly determined by its 



Habits and Life-history 578 



9. Mimetic Resemblance and Common Warning Colours more charac- 



teristic of the Female than the Male Sex 580 



10. The Space and Time Relationships of the Resemblances in Question... 582 

 IL The Resemblances which Insects of various Orders bear to those of 



another Order are produced in the most Diverse Ways 685 



12. The Resemblances within the Limits of the Order are also produced 



in tbe most Diverse Ways 595 



13. The supposed Direct Effect of Local Forces implies the Hereditary 



Transmission of Acquired Characters 601 



14. General Conclusions: Natural Selection as the Cause of Mimetic 



Resemblance and Common Warning Colours 601 



(1) Sistorical Introduction. 

 SuPEEFiciAL resemblances between animals, especially numerous 

 in Insecta, were known long before H. W. Bates's paper " Con- 

 tributions to an Insect Fauna of the Amazon Valley " was read 

 before the Linnean Society on November 21st, 1861, and published 

 in the 'Transactions ' the following year (vol. xxiii. p. 495). Some 



