LIST OF ILLUSTRATIONS 



Coloured Plates 



PAGE 



I. Mimicry of bees by flies in Brazil. (From Study, 

 1926) ...... Frontispiece 



II. Polymorphism in the moth Acalla comariana Zeller. 



(From Fryer, 1928) .... to face 102 



Illustrations in the Text 

 fig. 



1. Distribution of average number of vertebrae in the 



Atlantic Cod (Gadus callarias L.). (From Schmidt, 



193°) 49 



2. Correlation of yellow markings with climatic conditions 



in the wasp Polistes foederata. (From Zimmermann, 



I93 1 ) ; •_ 50 



3. Map of distribution of Eumenes maxillosus De G. adapted 



from Bequaert (1919) . . . . . .68 



4. Body- and head-lice. (From Sikora, 1917) . . . 75 



5. Frequency curve of variation in size of male and female 



Dasymutilla bioculata Cresson. (From Mickel, 1924) . 80 



6. (a) Map of distribution of races of the marmot, Marmota 



caligata ........ 83 



(b) Map of distribution of races of Marmota flaviventris . 84 



(c) Map of distribution of races of Marmota monax . . 85 

 (From Howell, 1915) 



7. Distribution of primary varieties of Partula otaheitana 



on Tahiti. (From Crampton, 19 16) . . . 86 



8. Comparison of means of colonies of Partula in Tahiti. 



(From Crampton, 19 16) . . . . .98 



9. Variation in the Pointed Snail in its colonies in Sussex. 



(From Toms, 1922) ...... 100 



10. Variation in the finch, Buarremon. (From Chapman, 



1923) ......... 106 



1 1 . Distribution of Buarremon brunneinuchus and B. inornatus. 



(From Chapman, 1923) . . . . . .107 



