Vol. AV.V. September, 1910. No. ./ 



BIOLOGICAL BULLETIN 



ACCESSORY CHROMOSOMES IX MAN. 



MICHAEL F. GUYER. 

 UNIVERSITY OF CINCINNATI. 



iblir.it ion of my papers on the sperm, i isis of 



tin guinea and of the rhirken respectively (Guyc-r '090, '< 



in \\ liirh was recorded tin- finding of a chromosome or chromosome. 



complex comparable- to the "odd," "accessory" or "X-elrmeiu," 



ile-i rilHxl so frequently of late as occurring in a \\i<le r.m-i . .f 



tin- Artliropoda, particularly the Tracheata, I have rx.imiiinl 



inatri-i.il from otlu-r \ertebratcs and can at present record it-; 



presence iii the rat, its probable occurrence in tin pigeon 



.ihhoii-li this \\ill require some further corroboration), ami ii> 



piiiious occurrence in man. Inasmuch as the material 



u- stu< l\ in the rat is in the hands of a student lor further 



iii\e-ti^aiion. I >hall confine myself in this pa|>er to a de-rrip- 



tioii ot tlu- t wo accessory chromosomes as found in man, together 



\\iih other leaimv> of human sjx;rmatoR:enesi- 



I i >r m\ studies on man 1 have l>een fortunate in l>eiiv s r able 



ibtain CM epti. -nally PIKK! material through the courte>\ of 



m\ (ollea^iii. I >r. Paul. < ' \Voolley. The subject from which 



the testicular material was secured was a negro thirty years of 



\\ ho h.nl ilie<l MuliK-nly from the rupture of an aortic aneuri-m 



1 no. 151,1.}; Pathological Records, the Cincinnati City 



II. spital). \ - was removed within l)etween an hour and 



an hour and a half after death while the body was still warm 



and >li< e- \\etv placed immediately into Gil-on'v and into 



-. fluid-. 



The mounted sections were from ti\e to twelve microns thick. 

 ( ,f tlu-m \\ere >tained in Heidrnhain'.- iron-lurmatoxylin 



