THE FUNCTION OF CONSCIOUSNESS. 503 



face downwards, the plasmodia migrate into deeper 

 regions still having a higher temperature. When the 

 cooling proceeds very gradually, which especially hap- 

 pens in large tan-heaps, the plasmodia may, in their 

 migration reach somewhat considerable depths, where 

 they then change into sclerotia. To find the sclerotia 

 of ^Ethalium in winter it is, therefore, not seldom 

 necessary to search through the mass of tan to a depth 

 of several feet. When the temperature again begins 

 to rise, the sclerotia again germinate, and movement 

 in the opposite direction takes place from the deeper 

 and cooler parts to the upper portions already warmed. 



"In the locomotion of the Myxomycetes, then, we 

 see extremely interesting cases of movements due to 

 stimulation. Heliotropism, geotropism, hydrotropism, 

 trophotropism, in general, are stimulus-movements, 

 and ultimately all growth depends on stimulus-move- 

 ment. It is the most primitive kind of protoplasmic 

 movement. Stimuli in fixed directions and constantly 

 repeated, produced, but only secondarily, fixed paths 

 of conduction, and responses of a quite definite kind 

 (reflexes). Thus arose nerves, and finally apparatus 

 for stirring up stimuli, arose sensation and will as 

 acquired and inherited faculties." 



In this lowest type of organic movement it is diffi- 

 cult to discern any cause for it different from those 

 which actuate higher organisms. What form of inor- 

 ganic energy can be cited as sufficient to cause the 

 organism to change its position with regard to stimuli 

 to self-preservation, and without regard to gravita- 

 tion, or any known form of attraction or repulsion? 

 In the Fuligo (tan flowers) a most pronounced ex- 

 ample of designed movement has been observed. 

 This form, in the amcebula stage, will, according 



