WENRICH: spermatogenesis of PHRYNOTETTIX MAGNUS. 65 



sometimes radiate out from the composite granule like the spokes of a 

 wheel from its hub. Such a stage corresponds to the bouquet stage 

 of Eisen ('00). At the end of the pachytene stage the granules 

 composing the composites separate out again, apparently without 

 having changed their identity (Plate 3, fig. 35-37). 



The tendency of the polar granules to remain on one side of the 

 nucleus may be interpreted as evidence of a somewhat persistent 

 polarity of the nucleus as a whole. It will therefore be convenient to 

 speak of that region of the nucleus where the majority of the polar 

 granules are congregated as the ■proximal pole, and the opposite side 

 as the distal pole, of the nucleus. 



In my description of the leptotene and zygotene stages it will have 

 been noticed that no mention is made of the contraction, or synezesis, 

 stage (McClung '05). Such a phenomenon has not appeared in my 

 material and, as has been claimed by McClung ('00, '05), Davis ('08) 

 and others, is probably not normal in the Orthoptera. 



I shall use the term synapsis in the same sense in which it was 

 originally used by Moore (*95), that is, to indicate the process of 

 coupling or conjugation of the chromosomes of the last spermatogonia 

 to form those of the jSrst spermatocyte. Following Wilson ('09), I 

 shall use parasynapsis to denote side-by-side conjugation, and telo- 

 synapsis to denote end-to-end conjugation. 



For the purpose of determining more accurately the history of the 

 changes undergone by the chromatin through the successive stages 

 outlined above, three individual autosome-pairs have been selected 

 for detailed study. To distinguish them from the other autosomes, 

 I shall call them the selected chromosomes. 



B. Synapsis. 



a. The Postspireme Stages. 



Of the various methods by which the diploid series of chromosomes 

 could unite in pairs to form the haploid, or reduced, series, the two 

 which have been more frequently defended are: — (1) that by which 

 the members of each pair unite end-to-end (telosynapsis), and (2) 

 that by which they unite side-by-side (parasynapsis). Evidence in 

 favor of both methods has been gained from observations on orthop- 

 teran material. The writer, without prejudice in favor of either view, 

 undertook to discover which of these processes occurs in Phrynotettix. 



