ORTHOPTERAN SPERMATOGENESIS 681 



The work of de Sinety ('01) upon Oedipoda, Stenobothrus, 

 and certain Phasmids was not done with a detailed consideration 

 of chromosome relationships and so it is not possible to bring it 

 strictly into line with more recent studies. Such a comparison 

 will however be valuable in showing the greater precision of our 

 present knowledge: (1) No adequate attempt is made to analyse 

 the members of the first spermatocyte complex in terms of the 

 spermatogonial chromosomes. (2) The first spermatocyte chro- 

 mosomes are formed by the transverse division of the chromatin 

 thread, which then divides twice longitudinally in planes perpen- 

 dicular to each other. There result, by different degrees of 

 separation and movement of these four parts, chromosomes in 

 the shapes of rings, loops, crosses, etc. (3) Through concentra- 

 tion these become the final metaphase chromosomes in which 

 the second longitudinal split is lost. (4) Because no distinction 

 is made between the Stenobothrus and Hippiscus types it is not 

 possible to compare the behavior of the various chromosomes 

 in the spindle. (5) No uniformity in the movements of the 

 chromatids in metaphase can be deduced from de Sinety's account 

 except that they separate along the first longitudinal cleft. 

 (6) The fiber attachment may be teraiinal, median, or sub- 

 terminal. Differentiation between conditions in Stenobothrus and 

 Oedipoda is not made. (7) Forms of chromosomes in the first sper- 

 matocyte anaphase depend upon the position of fiber attachment 

 and may be V-shaped with terminal attachment, double V-shaped 

 with median and double J-shaped with subterminal. (8) The 

 first spermatocyte division is longitudinal in the plane of the first 

 split. (9) Along the second longitudinal cleft the chromosomes 

 separate in the second speniiatocyte. There are accordingly two 

 longitudinal divisions and no reduction. 



Montgomery ('05) confined his Orthopteran studies to a single 

 species, Syrbula acuticornis, and came to a number of conclusions 

 very different from those reached by other investigators, although 

 in general the processes were conceived to be similar to those in 

 other Acrididae: (1) Twenty chromosomes were reported for 

 the spermatogonium, of which one pair constitutes the heterochro- 

 mosomes. These pairs might be distinguished by differences in 



