ORTHOPTERAN SPERMATOGENESIS 717 



that this be removed because the Stenobothrus form of chromo- 

 some, while rare in the Orthoptera, is very common in other 

 animals and in plants. Had these matters been understood 

 many extended reviews, seeking to reduce all maturation phenom- 

 ena to a type, upon the basis of chromatid relations in the first 

 spermatocyte metaphase, would not have been written. It is 

 barely possible that a complete understanding of synapsis condi- 

 tions may result in such a harmony, but with our present knowl- 

 edge of the subject the metaphase relations are very different 

 and point almost certainly to prereduction in Stenobothrus 

 rings and to post reduction in those of Hippiscus. The differ- 

 ence between these two types of annular chromosomes relate to 

 the fiber attachment and to the position in the spindle, the latter 

 being a consequence of the former. By some chance there is no 

 difference of opinion on these matters, and all observers agree 

 that in Stenobothrus the rings lie extended in the axis of the spin- 

 dle with fibers attaching somewhere near the middle of each of 

 the half rings that later enter the anaphase. There results 

 accordingly a reduction division. 



It is difficult to see how these sharply contrasting conditions 

 could be confused, yet neither de Sinety nor Davis, both of whom 

 studied Hippiscus-like chromosomes, differentiated between the 

 two varieties of rings. That this was due entirely to misinter- 

 pretation and not to varied conditions is rendered certain by com- 

 paring two adjoining figures of de Sinety, figure 125 showing the 

 Stenobothrus ring extended along the spindle with subterminal 

 fiber attachment, and figure 132 of Oedipoda, the only polar view, 

 with the rings lying in the equatorial plate with terminal attach- 

 ment of fibers. Davis also shows clear lateral views of the spindle 

 of Stenobothrus with extended rings (figs. 88, 91) and in text 

 figure N sketches of two cells in polar view with rings showing. 

 In both instances mistakes in determining the correct relation 

 of the Hippiscus rings to the archoplasmic fibers resulted in an 

 apparent uniformity. 



Stevens ('12) shows rings of this type in Ceuthophilus, Jordan 

 ('08) in Aplopus. 



