4 INTRODUCTORY 



But however long or short the plasmodial phase continue, the time of 

 fruit, the reproductive phase, at length arrives. When this time 

 comes, induced partly by a certain maturity in the organism itself, 

 partly no doubt by the trend of external conditions, the Plasmodium 

 no longer as before evades the light, but pushes to the surface, and 

 appears usually in some elevated or exposed position, the upper side 

 of the log, the top of the stump, the upper surface of its habitat, 

 whatever that may be; or even leaves its nutrient base entirely and 

 finds lodging on some neighboring object. In such emergency the 

 stems and leaves of flowering plants are often made to serve, and 

 even fruits and flowers afford convenient resting places. The object 

 now to be attained is not the formation of fruit alone, but likewise 

 its speedy desiccation and the prompt dispersal of the perfected 

 spores. Nothing can be more interesting than to watch the slime- 

 mould as its Plasmodium accomplishes this its last migration. If 

 hitherto its habitat has been the soft interior of a rotten log, it now 

 begins to ooze out in all directions, to well up through the crevices of 

 the bark as if pushed by some energy acting in the rear, to stream 

 down upon the ground, to flow in a hundred tiny streams over all 

 the region round about, to climb all stems, ascend all branches, to 

 the height of many inches, all to pass suddenly as if by magic charm 

 into one widespread, dusty field of flying spores. Or, to be more 

 exact, whatever the position ultimately assumed, the Plasmodium soon 

 becomes quiescent, takes on definite and ultimate shape, which varies 

 greatly, almost for each species. Thus it may simply form a flat, 

 cake-like mass, aethaliunij internally divided into an indefinite num- 

 ber of ill-defined spore cases, sporangia; or the Plasmodium may take 

 the form of a simple net, plasmodiocarp, whose cords stand out like 

 sw^ollen veins, whose meshes vary both in form and size; or more 

 commonly the whole protoplasmic mass breaks up into little spheroid- 

 al heaps which may be sessile directly on the substratum, or may be 

 lifted on tiny stems, stipitate, which may rest in turn upon a common 

 sheet-like film, or more or less continuous net, spreading beneath 

 them all, the hypothallus. In any case, each differentiated portion of 

 the Plasmodium, portion poorly or well defined, elongate, net-like, 

 spheroidal, elliptical, or of whatever shape, becomes at length a 



