CHROMOSOME COMPLEX OF SPEKMATOCYTES. 



319 



tion that the same chromosomes that are involved in the first 

 spermatocyte mitosis, where the spindle fills the entire cell, in 

 the preceding generation, the spermatogonia, divide around a 

 spindle that is so small as to be 

 practically negligible as a motor 

 apparatus for the movement of 

 the chromatin. The spermato- 

 gonial spindle is indeed so di- 

 minutive as to be almost invis- 

 ible among the relatively huge 

 chromosomes that surround it, 



and so short as to be a fraction 



of the 



somes. 



length of the chromo- 



If the mitotic figure is purely, 

 or even principally, a mechan- 

 ical arrangement for the separa- 

 tion of the chromosome halves, 

 then there would be some pro- 

 portion between the spindles of 

 successive generations which 

 have to do with the same chro- 

 mosomes. The ability of the 

 chromosomes to execute inde- 

 pendent movements is proven 

 by the action of the accesosry 

 in wandering to one pole of the 

 spindle in advance of the other elements, as well as by the long 

 series of movements performed by them in the prophases. 



4. Certain Chromosomes of Clwrtopliaga riridifasciata. 



Besides the instances of unusual chromosome associations 

 mentioned for Hesperotettix and Mcnniria I am able to bring for- 

 ward others which will serve to show that the conditions present 

 in these forms are not pathological or abnormal. The most pro- 

 nounced case of synapsis of spermatogonial chromosomes is ex- 

 hibited by Chortophaga, an CEdipodinse. I observed and photo- 

 graphed cases of this three years ago, but did not attach much 



FIG. 1 6. Late anaphase of second 

 spermatocyte of Mermiria. Here are 

 represented later stages in the separation 

 of such elements as are shown in the 

 preceding figure. 



