CHAPTER XL 



SLIME MOULDS, BACTERIA, AND YEASTS. 

 PROVIDING MATERIALS. 



The materials needed for the work of this chapter can be obtained 

 at any time of the year, as directed under the observations. It is a good 

 plan, however, to gather the sporangia of slime moulds whenever they 

 are found in their prime, and preserve them as directed on page 370. 



OBSERVATIONS. 



Slime Moulds. 



142. Hunt beneath the bark of rotting logs or amongst 

 the moist leaf mould of woods for yellowish or gray slimy 

 growths ; the plasmodia of slime moulds. Cut off a portion 

 of the log bearing the plasmodium, expose to the light and 

 make note of the result. Allow another portion of the log 

 bearing the plasmodium to dry in the dark, and note the 

 result. 



143. Place some of the plasmodium under a bell jar 

 between pieces of moist felt paper (carpet paper will 

 answer) and keep the preparation in the dark, and moist 

 but not wet. The plasmodium will probably grow out over 

 the paper, and its translocation should be observed from 

 time to time. Make moist chamber preparations of the 

 plasmodium as directed under Observation 108, page 103. 

 Watch the circulation of the protoplasm with a medium 

 power of the compound microscope, and make drawings in 

 which the direction of movement is indicated by arrows. 



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