Myxomycetes and Schizophytes 153 



should not be thicker than 2 /* or 3 JLI. The safranin, gentian-violet, 

 orange combination is good for a study of the general development 

 and for some cytological features, but iron-alum haematoxylin is 

 better for nuclear details. 



Spores of most myxomycetes will germinate as soon as they are 

 thoroughly ripe, and, during the first year, germination is more prompt 

 than in case of older spores. Fresh spores may germinate in half 

 an hour; the time may extend to several hours; spores two or three 

 years old may germinate in three or four days, or may not germinate 

 at all. We have never succeeded in germinating spores which were 

 more than three years old. The longevity is doubtless different 

 in different species. In most cases, spores will germinate in water, 

 if they will germinate at all. For small cultures, the hanging-drop 

 method, described on p. 73, may be used. 



Plasmodia may be raised by sowing spores on moist, rotten bark 

 or wood and placing the culture under a bell jar, where the moist, 

 sultry condition favorable to their growth is easily imitated. Plas- 

 modia may be got upon the slide by inclining the slide at an angle of 

 about 15, with one end of the slide at the edge of the plasmodium, 

 and allowing water to flow very gently down from the upper end of 

 the slide to the lower. The proper flow of water could be secured 

 by dropping water from a pipette, but a less tedious plan is to arrange 

 a siphon so as to secure a similar current. The plasmodium will 

 creep up the slide against the current, furnishing an excellent illus- 

 tration of rheotropism. Enough plasmodium for an illustration may 

 be formed in two or three hours. Examined under the microscope, 

 the preparation should give an excellent view of the streaming 

 movements of protoplasm. 



The following is another method for getting the plasmodia upon 

 the slide: Place the slides upon a pane of glass and upon each slide 

 place a small piece of plasmodium-bearing wood. Cover with a bell 

 jar. Wet blotting paper or a small dish of water included under the 

 jar will help to create the warm, sultry atmosphere necessary. The 

 slides may be covered with the plasmodium in a few hours. Per- 

 manent preparations may be made by immersing the slide in chromo- 

 acetic acid, then washing and staining without removing the 



