Contributions from the zoological laboratory of the museum of comparative zoology at 



HARVARD college. NO. 274. 



CHROMOSOME STUDIES 



i. taxonomic relationships shown in the chromosomes of 

 tettigidae and acrididae : v-shaped chromosomes and 

 their significance in acrididae, locustidae, and gryl- 

 lidae: chromosomes and variation 



WM. REES B. ROBERTSON 



University of Kansas 



FOUR TEXT FIGURES AND TWENTY-SIX PLATES 



CONTENTS 



Introduction 180 



Taxonomy 181 



1 . Taxonomy and chromosomes 181 



2. Taxonomic characters compared 183 



The chromosomes 186 



1. Tettigidae 188 



1. Acridium granulatus Scudd 188 



a. Chromosomes of the male germ cells 188 



b. Chromosomes of the male somatic cells 190 



c. Chromosomes in the female 191 



d. Summary for Acridium granulatus 197 



2. Acridium incurvatus Hanc 197 



3. Acridium ornatus Harris • 199 



4. Acridium obscurus Hanc 199 



5. Paratettix cucculatus Morse 201 



6. Paratettix texanus Hanc 202 



7. Tettigidea parvipennis pennata Morse 202 



8. Tettigidea parvipennis Morse 203 



9. Unequal homologous chromosomes 205 



2. Truxalinae (Acrididae) 206 



1. Syrbula acuticornis Bruner 207 



2. Chorthippus (Stenobothrus) curtipennis Scudd 210 



3. Chorthippus biguttulus Linn 215 



4. Resume on Chorthippus and Syrbula 215 



3. Oedipodinae (Acrididae) : Chortophaga viridifasciata, Dissosteira 



Carolina 216 



4. Acridiinae (Acrididae) : Melanoplus femoratus 217 



5. Locustidae and Gryllidae: Decticus verrucosus, Steiroxys trilineatas, 



Gryllis domesticus, Jamaicana subguttata and J. unicolor 217 



179 



JOURNAL OF morphology, VOL. 27, NO. 2 

 JUNE, 1916 



