AUTHOR S ABSTRACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE JULY 21. 



THE MULTIPLE CHROMOSOMES OF HESPEROTETTIX 

 AND MERMIRL\ (ORTHOPTERA) 



CLARENCE E. McCLUNG 



Department of Zoology, University of Pennsylvania 



EIGHT PLATES 



CONTENTS 



I. Introduction 519 



II. Chromosome conditions in the genus Hesperotettix 521 



1. General observations 521 



2. The complex of H. speciosus 522 



3. The complex of H. pratensis 524 



4. The complex of H. brevipennis 525 



5. The complex of H. festivus 526 



6. The complex of H. viridis 526 



III. Chromosome conditions in the genus Mermiria 530 



IV. General considerations 536 



1. Chromosome numbers in the Acrididae 538 



2. Chromosome numbers in general 545 



3. Chromosome sizes 554 



4. Chromosome forms 558 



5. Chromosome behavior 57 1 



6. Chromosome distribution 573 



7. Chromosome individuality 577 



8. Chromosome specificity 585 



V. Summary 587 



VI. Bibliography 589 



I. INTRODUCTION 



Under the title ''The chi-omosome complex of Orthopteran 

 spermatocytes" ('05) I described certain unusual conditions in 

 these cells, among them the union between the accessory chromo- 

 some and particular euchromosomes to form multiple chromo- 

 somes. At the time my material was limited and I was able to 

 present only a partial account. Since then I have been accumu- 

 lating a large series of specimens which have been studied both 



519 



