H IZT- Li 2. 
THE SLIME MOLDS OF OHIO 
By 
E. L. FULLMER 
INTRODUCTION 
The Slime Molds comprise about 400 species. Of these some 200 have 
been collected in the U. S. and about 150 have been found in Ohio. Every 
wood lot affords a number of species. The writer has collected 64 species 
from an area of land of less than a quarter section at Cedar Point, Ohio. 
These 64 species were obtained by spending a few days each summer for 
a period of years in careful search for specimens. Not more than 30 
species were seen during any one season, but each seasons collecting 
resulted in species being found that were not seen before in that area. 
Doubtless the number found in this small area could be extended by 
further careful collecting. 
In their development. Slime Molds pass through two very different 
stages, a vegetative, consisting of motile amoeba like cells, and a 
reproductive, consisting of spores which are usually found in sporangia. 
If a spore chances to fall in a favorable place it will germinate. In 
germinating the dense spore wall is ruptured and the protoplasmic 
contents escapes as an amoeba like cell and having an amoeboid movement. 
In the case of the Myxomycetae the amoeba like cell soon develops a 
flagellum or whip like projection, and by the lashing of this the cell is now 
propelled in a dancing or very jerky manner. (Plate X, figs. 1, 2, and 3.) 
These cells multiply rapidly in number and after a time a large number of 
cells, having lost their flagella, coalesce into a network, the plasmodium. 
The cells of the plasmodium are destitute of cell walls but the merging 
cells retain their nuclei and continue to increase in number by division. 
Plasmodia may often be found under the damp bark of old logs or upon 
other decaying organic matter that is moist and that is not exposed to the 
light. In color they are commonly yellow but some forms are white, 
others cream colored, still others red. They consist of a slimy reticulated 
mass and have a peculiar motion. (Plate X, figs. 4, 4a, and 4b). The 
substance of any one branch will flow in one direction for a brief time, 
stop and then flow in the opposite direction for a short time, however, 
flowing a little farther in the one direction than in the other and thus 
giving the plasmodium a forward movement. It may thus creep about 
upon and within a substance upon which it is feeding. It may even be 
induced to creep upon a glass slide and’ it may then be examined with a 
microscope and the movement studied. 
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