220 BOTANICAL GAZETTE [ OCTOBER 
into uninucleated masses, and this is the current statement of 
botanical text-books. 
Rosen (17) made a very thorough study, as he describes it, 
of Fuligo septica. He finds nuclei of two kinds, one poor in con- 
tent and containing a so-called middle-body, and the other so 
densely filled with stainable substances as to appear almost 
homogeneous. The relative number of these two types of nuclei 
vary at different stages in the development of the slime mold. 
Nuclear division occurs prior to spore formation, but the process 
is described as much simpler than in the higher plants. Rosen 
thinks it belongs to the karyokinetic type, but it is doubtful 
whether a spindle figure is formed, etc. The cleavage 1S post 
tively stated to be simultaneous, and to take place by the depo- 
sition of a network of granular plates which cut the protoplasm 
up at once into polyedric uninucleated spores. These plates are 
said to show microsomes very plainly, the latter being placed at 
right angles to the plane of the plate. 
As will be seen below, my own observations on Fuligo have 
led to entirely different results from those of Rosen. es 
convinced that his two forms of nuclei are due to inequalities 
in fixation such as sometimes occur. As to the method of 
nuclear division and spore formation I am certain that Roset 
failed to find material in the stages when these processes ce 
His description of nuclear division must have been based 0" 
resting nuclei whose contents happened to be somewhat yer 
ally placed. As for the network of granular plates with mict” 
somes such as he figures, 1 am convinced that no such struct , 
“are to be found in Fuligo at any stage of development. i iy 
difficulties in the way of obtaining accurate results in ee 4 
of fungus cells and nuclei are great, but not sufficien 
such slipshod results as those of Rosen in the paper 
sideration. a 
A summary of our present knowledge of the Myxomy""" 
has recently been published by Jahn (g), and agai h 
be made to it for a further account of the literatur® : 
group. » 
under cof 
