AtTTHOR S ABSTRACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, OCTOBER 17 



BLUE-GREEN CATERPILLARS: THE ORIGIN AND 



ECOLOGY OF A MUTUATION IN HEMOLYMPH 



COLOR IN COLIAS (EURYMUS) PHILODICE 



JOHN H. GEROULD 



Dartmouth College, Hanover, New Hampshire 



ONE TEXT FIGURE AND ONE COLORED PLATE (siX FIGURES) 



CONTENTS 



Introduction 385 



Origin of the mutation 389 



Effect of the. mutation on the egg 392 



Blood and body color of the larva 393 



Color of the pupa and of its cuticula 393 



Imago and its eye color 394 



Discussion 395 



Effect of blue-green blood on the cocoon-color of a parasite 396 



Discussion 397 



How lamarckian factors may reach the genes 398 



Action of environmental factors and genes upon certain blood pigments 400 



Inadequacy of the presence-absence hypothesis' to explain grass-green vs. 



blue-green blood color 402 



Elimination of blue-green mutants by natural selection 402 



Inheritance of the mutation 403 



Table 1 404 



Vigor of the mutant caterpillars 405 



Similar mutants in plants and animals 406 



Factors affecting the color of blood and cocoon in the silkworm 408 



Summary 409 



Literature cited 411 



INTRODUCTION 



In the course of an investigation into the inheritance of dimor- 

 phism (white and yellow female varieties of the butterfly) 

 in Colias philodice involving close inbreeding, a remarkable 

 mutation in blood color occurred during the summer of 1920. 

 The mutation is extraordinary in that it affects pigments that 

 are derived without much modification from the chlorophyl of 



385 



