A COMPARATIVE STUDY OF THE CHROMOSOMES 

 IN ORTHOPTERAN SPERMATOGENESIS 



CLARENCE E. McCLUNG 



Department of Zoology, University of Pennsylvania 



TEN PLATES 



CONTENTS 



I. Introduction 652 



II. The spermatogonia! chromosomes 655 



a. Hippiscus type 655 



b. Stenobothrus type 655 



c. Comparisons 657 



1. Acrididae 657 



2. Locustidae 659 



3. Gryllidae 660 



4. Phasmidae 660 



5. Blattidae 660 



6. Forficulidae 661 



d. Summary of results on spermatogonia 661 



III. Synapsis period 662 



IV. Chromosomes of the first spermatocyte prophase 662 



a. Evidence for chromosome individuality 662 



1. Chromosome reproduction 663 



2. Constancy of complex in species, etc 663 



3. Definite relation to archoplasmic fibers 663 



4. Individual peculiarities of behavior 664 



b. Relation of the first spermatocyte chromosomes to those of the 



spermatogonium 665 



1. Accessory chromosome 665 



2. Euchromosomes 665 



c. Forms of prophase tetrads 667 



V. Chromosomes of first spermatocyte metaphase 670 



a. Identification of metaphase chromosomes of the first spermato- 



cyte with those of prophase 670 



b. Movements of chromatids in metaphase 671 



c. Relation of chromosomes to archoplasmic fibers 674 



1. Hippiscus type 674 



2. Stenobothrus type 675 



VI. Chromosomes of second spermatocyte metaphase 678 



651 



JOURNAL OF MORPHOLOGY, VOL. 25, NO. 4 



