704 C. E. McCLUNG 



composition of the first spermatocyte chromosomes. Objection 

 has been made by JVIontgomery that they are comphcated and 

 difficult to interpret, but I do not befieve that this is justified. 

 He also states that they are transitory prophase stages which 

 rarely persist into the metaphase. This is certainly an error, as 

 Robertson has shown in the same genus studied by Montgomery, 

 where there are always at least two in each metaphase complex 

 and may be as many as seven. A fruitful source of error in deter- 

 mining the method of division in the ring chromosomes lies in 

 the failure to discriminate between such rings as appear in Hip- 

 piscus and most other Acrididae, from those of Stenobothrus. 

 In general it may be said that the mere structure of the ring is 

 fairly interpreted, in most cases, but that its relation to the 

 archoplasmic fibers and its actual division in the first spermato- 

 cyte mitosis have been much misunderstood. Because ,of its 

 significance I shall make a careful analysis of this form of tetrad, 

 as reported in the Orthoptera, and hope to make clear the cause 

 for the confusion that has arisen. 



That we deal here with a universal form is indicated by the 

 fact that it is described and figured by Wilcox, Sutton, de Sinety, 

 Baumgartner, Montgomery (prophase). Farmer and Moore, 

 Stevens, Moore and Arnold, Otte, Wassilieff (prophase), BruneUi, 

 Pinney, Davis, Robertson, Gerard, Jordan, Alorse, Granata, 

 Meek, Nowlin, Hartman, Vejdovsky, Carothers and myself. 

 Indeed it may be said that practically without exception every 

 investigator of recent years who has made a careful study of the 

 maturation stages in the Orthoptera has seen and figured annular 

 chromosomes. It would appear certain, therefore, that if a 

 knowledge of the structure and division of such elements is 

 attained we shall have made an important and significant advance 

 toward a comprehensive understanding of all chromosomes in 

 all the members of the order. 



Essential to such an understanding is a knowledge of the 

 exact structure of the ring in the prophase. This necessity I 

 have always felt, and in my first paper on the Acrididae ('00, 

 p. 94) appears this statement in italics: "Too much importance 



