THE SLIME FUNGI. 51 



Hofmeister has pointed out, the movements of protoplasm 

 in the cells of the higher plants. These plants grow 

 better in the dark than in the light, and Sachs has shown 

 that they exhibit a marked irritability to the influence 

 of light. The Flowers of Tan are favorable plants for 

 study. These develop on piles of tan bark and on decay- 

 ing leaves and bark during hot, sultry weather. They 

 appear suddenly when the conditions of heat and moisture 

 are favorable, and run through their course of existence 

 within the space of a few days. If the conditions are 

 changed, they disappear. If masses of the tan on which 

 they have begun to develop are placed in the dark, the 

 slime spots collect on the surface ; if strong light is allowed 

 to fall on them, the spots creep down into the masses of 

 tan. It is, however, only during the earlier, plasmode 

 stage of their development that they exhibit this irritability 

 to light. During the later stages of development, they 

 flourish in strong light. Sachs has also shown that the 

 Slime Fungi are influenced by an apogeotropic stimulation 

 which causes them to ascend the stems of plants, or even 

 glass plates placed vertically in the substratum on which 

 they grow. Growths are thus easily obtained for micro- 

 scopic study. 



Recent theories attribute certain malarial diseases to 

 species of the Slime Fungi which find entrance to the 

 human blood through the medium of drinking water and 

 there multiply in the amoeboid condition. In the blood 

 they are combated and eaten by the colorless amoeboid 

 corpuscles the phagocytes. Victory by the phagocytes 

 means recovery of health ; victory by the Slime Fungi 

 means death. 



In their earlier stages these Slime Fungi form continu- 

 ous, or nearly continuous, masses of protoplasm, without 

 cell walls, without fixed shape, and without green color. 

 They are whitish, colorless, or of a yellow sulphur color, 



