. ae 
rece, BRIEFER ARTICLES " 463 
mizing the importance of the nucleus, he questions whether the organ 
he described in Spirogyra is BRown’s nucleus.® 
SCHLEIDEN, intentionally or otherwise, does not mention this work 
of MEYEN in his Phytogenesis nor in the Grundziige; he names BROWN 
the discoverer of the nucleus, and this statement in these widely 
circulated publications is to a great extent the source of the current 
opinion that Brown gave the first description of the nucleus.— 
W. Marquette, University of Wisconsin, Madison, Wis. 
NUCLEAR PHENOMENA IN PUCCINIA PODOPHYLLI 
(PRELIMINARY NOTE) . 
In the mycelium of Puccinia Podophylli which is to give rise to aecidia 
and spermagonia a binucleate condition prevails, the nuclei being asso- 
ciated in pairs and dividing conjugately throughout all parts of the 
mycelium, even before there is any indication of aecidium formation. 
This condition, however, is not constant. Uninucleate cells are occa- 
sionally observed, while those with more than two nuclei.are very 
common. 
The aecidium arises in a dense tangle of hyphae beneath the epidermis 
of the host. Certain cells in the midst of this tangle enlarge and become 
the “basal cells” of the aecidiospore chains. Whether any one of these 
cells is simply the enlarged termination of a hypha or is the product of 
the fusion of two cells, as originally described by CHRIsTMAN for certain 
aecidia of the caeoma type, is not clear. Appearances have been ob- 
served which seem to indicate that such a fusion may occur, but any 
final conclusion upon this point is at present unwarranted. No migra- 
tions of nuclei between cells of the same or different hyphae can be 
recorded. The young basal cells contain two, three, or four nuclei, 
which at this stage become very large. The very frequent occurrence of 
four-nucleate basal cells upon a prevailingly binucleate mycelium is a 
further indication that such cells may not be of simple origin. 
The aecidiospores, which are formed with intercalary cells in the 
usual manner, contain two, three, or four nuclei, depending upon the 
humber contained in the basal cells from which they are derived. In 
older chains only two of the basal cell nuclei continue to function in 
this capacity, so that the binucleate spores finally far outnumber the 
others, 
° It is to be noted that vol. I of the Neues System der Pflanzen Physiologie was 
published a year earlier than SCHLEEN’s Phytogenesis. 
