MITOSIS IN SYNCHYTRIUM 
4 wits SOME OBSERVATIONS ON THE INDIVIDUALITY OF 
THE CHROMOSOMES: 
ROBERT F. GRIGGS 
(WITH PLATES XVI-XVIII) 
_. The nuclei of Synchytrium decipiens, a leaf parasite of the hog 
F peanut, were shown in previous papers to be derived very largely by 
-amitosis. Several sorts of amitosis were observed, two of which, 
nuclear gemmation and heteroschizis, differ considerably from the 
“ordinary. process of amitosis. The nuclei derived by these direct 
_ divisions were shown to be persistent, and some of them were observed 
: _to divide by mitosis. This with other facts led me to the conclusion 
4 “that the nuclei derived by these processes of amitosis are normal, 
The purpose of the present paper is to describe the mitoses which 
4 follow, to correlate them with the amitoses, and to discuss the theo- 
_ Tetical bearing of the facts thus presented. 
I would here repeat my acknowledgments to my friend, Professor 
or. L. STEVENS, of the North Carolina College of Agriculture and 
_ Mechanic Arts, who furnished the material used in the investigation 
and gave the suggestions that originally aroused my interest in the 
_ Problem. The sections were cut 2-10 thick and stained with 
_ Haidenhain’s iron alum hematoxylin and with anilin safranin and 
_ gentian violet. 
c As in coenocytes generally, all the nuclei in a cyst pass into mitosis 
3 simultaneously and divide with equal rapidity, so that all of them are 
very nearly in the same stage throughout. This fact may be utilized 
for Overcoming one of the most serious obstacles encountered in 
2 investigating the cytology of this plant—the difficulty of estimating 
_ the relative ages of the different structures in the absence of any 
& ‘Contribution from the Botanical Laboratory of the Ohio State University, 
; No. XLIX. 
339] [Botanical Gazette, vol. 48 
