and Laboratory Methods. 1799 



9. Note — To obtain Paramoecia, let a mass of Spirogyra or other water 

 plants decay in a jar of water exposed to the air. The Paramoecium is one of 

 the most highly developed and specialized animals belonging to the sub-kingdom 

 Protozoa. 



IX. Slime Moulds. Class, Myxomycetes. Order, Myxogastrales. 



The Myxomycetes are a group of organisms which approach very near to 

 the animal kingdom, forming one of the several transition groups from the lower 

 plants to the lower animals. They have developed a very complex life history, 

 although they are very simple plants. They usually grow on decaying logs and 

 stumps, and may be kept dry in the encysted or resting stage for an indefinite 

 length of time, and studied when convenient. 



(a) Lycogala epidendrum (Buxb.) Fr. 



1. Make a sketch showing the naked eye characters of individuals in the 

 resting stage (aethalia), and how they are situated on the wood. Describe. 



2. Moisten some of the downy material (capillitium) and a piece of the outer 

 enveloping layer (peridium) in alcohol, and mount in water. Examine under 

 high power. Is there any cell structure in the capillitium or peridium ? Draw 

 a part of the capillitium, showing the peculiar markings. 



3. Draw a few of the individuals (scattered through the capillitium) in the 

 resting stage (spores), and describe. 



(b) Hemitrichia clavata (Pers.) Rost. 



1. Mount one of the sporangia and sketch under low power, showing the 

 stalk of the sporangium, the broken peridium, and the mass of capillitium 

 threads. Describe shape, color, etc. 



2. Under high power draw some of the capillitium threads, showing all 

 details carefully. 



3. Draw some of the individuals in the spore stage. 



(c) Stemonitis fusca (Roth.) Rost. 



1. Mount and draw one of the plume-like sporangia under the dissecting 

 microscope, showing the hypothallus, stalk, columella, and capillitium. 



2. Under high power, draw part of the capillitium, showing how it is 

 attached to the columella. 



3. Draw some of the spores. 



(d) Plasmodium. 



1. Examine under the dissecting microscope, and describe the plasmodium 

 of a myxomycete in the moist living condition. This can usually be found on 

 decaying logs during the spring, summer, and autumn. If living material is not 

 at hand, examine pieces of plasmodium preserved in alcohol. 



2. The flagellate stage of many species of myxomycetes may be obtained 

 by simply making hanging drop cultures with water, or water in which decaying 

 wood has been soaking. Fresh spores of Lycogala will germinate in a day or 

 two, and the preparation can be examined from time to time under the high 

 power. 



Ohio State University. JOHN H. SCHAFFNER. 



