324 THE AMERICAN MONTHLY [Nov 



brings small assistance to the systematist. In fact, the 

 color depends no doubt upon the presence in the Plasmo- 

 dium of various matters, more or less foreign, unassimi- 

 lated, possibly some of them excretory, differing from 

 day to day. In its plasmodial state, as has been 8aid,the 

 Slime-mould affects damp or moist situations,and is found 

 during warm weather in humus, on piles of rotten leaves, 

 straw, but especially on and in the wet tissues of rotten 

 stumps and logs. In such a situation the protoplasm 

 spreads over all moist surfaces, creeps through the inter- 

 stices of the rotting bark, spreads between the cells, be- 

 tpeen the growth-layers of the wood, runs in corded vein- 

 like nets between the wood and bark, and finds in all 

 these cases nutrition in the products of organic decom- 

 position. Such a Plasmodium may be divided, and so 

 long as suitable surroundings are maintained, each part 

 will manifest all the properties of the whole. Parts of 

 the same plasmodium will even coalesce again. If a piece 

 of plasmodium-beariug wood be brought indoors, be pro- 

 tected from desiccation by aid of a moist dark chamber, 

 not too warm (70" F.), the organism seems to suffer little 

 if any injury, but will continue for days or weeks to man- 

 ifest all the phenomena of living matter. Thus, under 

 such circumstances, the plasmodium will constantly change 

 shape and position, can be induced to spread over a plate 

 of moist glass, and so be transferred to the stage of a 

 microscope, there to exhibit in the richest and most inter- 

 esting and abundant fashion the streaming protoplasmic 

 currents. As just indicated, the plasmodia follow mois- 

 ture, creep from one moist substance to another, especi- 

 ally follow nutritive substrata. They seem also to secure 

 in some way exclusive possession. I have never seen 

 them interfered with by hyphsB or enemies of any sort, 

 nor do they seem to interfere with one another. 



The plasmodial phase of the £lime-mould, like the hy- 

 phal phase of the fungus, may continue a long time ; for 



