ACCESSORY CHROMOSOMES IN MAN. 



LAXATIOX OF PLATI I 



VI re made with the aid of a camera luoi-hi; their nuit;ni- 



1,550 diameters. While : 



Me, no attempt has been ma the 



> beyond general appearances and relations. Ir 

 '>mes were not in the same local plane they h.. 



My in the most favorable plane and then corr --iMi- 



i run ae drawings of such individual < 



:ng. 



1 ate p;- phase of spcrmatogonial division showing tui-nty-tu 

 Chromosomes lying to one side of the in 

 lie two accessories. 



us of primary spermatocyte showing - 

 >li. 



.. 3. Nucleus of primary spermatocyte showing the 

 nuclear contents, also two persisting nucleoli. 

 Flu. 4. I. ate prophasc of division in a primary spermato- 

 tiiosomes. The two lying to one side of the main group 



. 5- I. air of division in a primary spermatocyte sho\\inu t\\ 



the two accessories are not readily identified. 



I-'ius. 6. 7. 8. 9. Mclnphases of divisions in primary 

 \vo accessories in characteristic positions passing ea: 

 AS also two precociously diverging daughter chromosomes. 



.. 10. One end of a late ana phase of division in .1 

 twelve chromosomes (10 plus a accessory). 



.. n. I one end of a late anaphase of divi < ptim.u 



tig ten chromosomes, the accessory ch; 

 . a prophasc of division in a 

 in which tl have remained univalent. 



I- 1 ius secondary spermatocytes ol \\ ! 



i late prophasc, the other more than live chn>! 

 two accessory) in met.i: 1 lu-se two 



niK tli. :.>n of a primary spri te in which t-n 



and ten plus the two accc> "tlu-r. 



li i-condary spermalocytes. Oiu-, ! :i\i. !.!. 



-ln'u at one pole; the chromoson 



unting although there shnul-1 ! li\' 

 il.ii' \-en chromosomes in late pn>ph.. 



I- h ise of division in a \\hidi 



,i.| tin- t\\" iiromosomes, showing seven clirnnin-iini-- in all. 



l-'h.. i :i in a sf'"iiilai . -hi >\\ini; still at 



Hiati'i ,i l.iuuin.c cliii'in.itic mass which i- pi"li.il.l\- the t\\- ry chm- 



.iltlii>ui;h it cuiilil nut he pn>iti\'ely ident 1 :ich. 



