1 6 W. J. BAUMGARTNER. 



There is a pair of very large chromosomes in the spermatogonia 

 and a single very large one in the spermatocyte. In Spinax there 

 are graded size differences of chromosomes which they compare 

 with Montgomery's and Button's results. They think the num- 

 ber of large chromosomes and small ones is constant but have 

 not proven this. The large chromosomes form rings. The 

 small ones form before mitosis mostly rods, seldom rings " haufig 

 Stabchen, selten Ringe." In the equatorial plate the chromo- 

 somes retain their shape. 



Here we have then from the recent papers, McClung, Sinety 

 and Schreiner, evidence that the shapes found in the prophases 

 are still found in the metaphase. Their drawings do not show 

 as many different forms in the metaphase as in the prophases, but 

 some are probably hidden. In Gryllus all the various shapes in 

 a cell are seen to best advantage in a late prophase, but I believe 

 all the shapes are still to be seen in metaphase. A careful com- 

 parison of my Figs. 1 1 and 12, late prophases, with Figs. 14 and 

 1 6, metaphase will prove that the same shapes are found in earlier 

 and later stages. The different kinds of attachment of the 

 mantle fibers can not account for different forms in the prophases, 

 although it may in the metaphase. Fig. 1 1 is very instructive. 

 The chromosomes are still granular and rough in contour yet we 

 find two rings, the number probably found constantly, and two 

 crosses, a number frequently observed. 



That these various shapes are artefacts as Korschelt and Heider 

 (14) suggest, is made very doubtful by the fact that they are 

 shown by my material fixed in very different reagents. They 

 are shown in my sections and in my smear preparations. Besides 

 the great army of investigators have used all kinds of fixatives 

 and yet have found them. 



That they are not simply stages through which the chromatin 

 must pass to get into the v or horseshoe shape of the anaphase 

 as Lebrun (15) has assumed, is combated by the long continua- 

 tion of the same form from the early prophase to the anaphase. 

 To reach such an end would need only one type of chromosome 

 form in a single nucleus at any one time. This is contrary to 

 the observation of the majority of workers who have observed 

 chromosome differences. 



