716 C. E. McCLUNG 



not cross from, one side to the other but remain constantly super- 

 imposed. These conditions have been clearly worked out by 

 my students and myself on all the forms studied, but have not 

 generally been understood. An exception to this statement is fur- 

 nished by Granata who in his figure 28 and text figure 1, o, (fig. 141) 

 shows accurately the structure of the looped chromosomes. All 

 considerations of uniformity in chromatid structure and move- 

 ment speak against the transposition of structures to the opposite 

 pole of the spindle. Boveri has fully discussed this matter in 

 relation to Ascaris chromosomes. 



g. Relation of rings to crosses. Crossed ends of chromosomes 

 when viewed across the equatorial plate, en face, would necessarily 

 appear displaced laterally — they would not be superimposed 

 in one plane. Despite the number who have advocated this 

 relation not one has shown a figure of a chromosome in such a 

 position. The omission is significant, for appearances of this 

 kind are not to be found. Such an aspect of the ring is a crucial 

 test of de Sinety's conception. From this point of view, indeed, 

 the rings are of the same appearance as crosses, or, viewed some- 

 what obliquely, show clearly the extended ends directly over each 

 other and with the lateral parts of the annulus merging symmetri- 

 cally into each (figs. 130, 133)^ 



So far as the prophase is concerned, the rings in Steno- 

 bothrus, Chorthippus, Chloealtis and the unidentified species 

 which I have figured — which I shall speak of as the Steno- 

 bothrus type — do not seem to show any differences from the 

 ones found in Hippiscus and other similar forms. In the 

 metaphase, however, it is clear that they bear a different 

 relation to the archoplasmic fibers; and, by comparison with the 

 chromosomes of the spermatogonium and second spermatocyte, 

 it appears that this is a constant feature of the organization 

 of certain ones of the complex. This is made sure by the work 

 of all investigators who have studied Stenobothrus, but was em- 

 phasized by Davis. A failure to appreciate the difference be- 

 tween the rings of Stenobothrus and Hippiscus types has been 

 responsible for much of the confusion that exists in the literature 

 regarding Orthopteran spermatogenesis. It is very necessary 



