162 THE BEAUTIES OF NATURE chap. 



decaying leaves, under bark and in similar 

 moist situations, are still more remarkably 

 animal like. They are never fixed, but in 

 almost continual movement, due to difEerences 

 of moisture, warmth, light, or chemical action. 

 If, for instance, a moist body is brought into 

 contact with one of their projections, or 

 " pseudopods," the protoplasm seems to roll 

 itself in that direction, and so the whole 

 organism gradually changes its place. So 

 again, while a solution of salt, carbonate of 

 potash, or saltpetre causes them to withdraw 

 from the danger, an infusion of sugar, or tan, 

 produces a flow of protoplasm towards the 

 source of nourishment. In fact, in the same 

 way it rolls over and round its food, absorbing 

 what is nutritious as it passes along. In cold 

 weather they descend into the soil, and one 

 of them (CEthalium), which lives in tan pits, 

 descends in winter to a depth of several 

 feet. When about to fructify it changes its 

 habits, seeks the light instead of avoiding it, 

 climbs upwards, and produces its fruit above 

 ground. 



