332 



Mycologia 



journey was accomplished, no doubt on schedule time. Just why 

 this journey was made it is hard to say, in view of the patent fact 

 that for the Plasmodium many another was quite open; much 

 easier of accomplishment one would say, since other courses lay on 

 the level, or even, gravity now favoring, downward amid recesses 

 of rotting leaves and wood, whence the fountain welled. JEthalium 

 is surely not geotropic, nor hydrotropic, since it now moved from 

 these directions; neither was it heliotropic, nor even phototropic, 

 in its turning; the gloom of the overshadowing box affected not 

 the culmination of some overmastering push with which the move- 

 ment started. Thermotropism there may have been, but the heat 

 difference between the upper exposed portion of the boulder and 

 that buried slightly in the forest mould could hardly have been 

 great. In any case, light and warmth had been for days quite as 

 tempting as in the hour the movement started; the impulse must 

 have some other probably internal physiologic origin ; doubtless 

 some change molecular, since the outcome is maturity and fruit. 



The biologist might go on to say that since the myxo is repro- 

 duced by spores distributed by air currents, or perchance the wind, 

 only such fruits as rise above the general, local level have superior 

 chances in the game of life ; success is with those that climb ; how 

 the climbing is accomplished the biologist does not say. 



But here the physicist may help us much. He steps in to say 

 that every fluid drop or mass meets its environment by a skin, a 

 film in tension, surface-tension, and this in case of your plasmodic 

 stream holds fast sufficient to prevent gravity from pulling your 

 hardy climbers from the Matterhorn, even from the overhanging 

 shelf ; while some internal, molecular changes in the c}^toplasm 

 itself, doubtless of physiologic import as the biologist suggests, 

 sends the climber up and on to the fulfilment of physiologic 

 function. 



But TEthalium furnishes a special case. Not every myxo is by 

 any means so rich either in material or equipment, but all aspire; 

 generally speaking, all, even the most minute, show strange ambi- 

 tion, strive to reach upward or outward, if but a little way toward 

 the open air. The behavior of Mthalium (most students say 

 Fuligo) is strange enough, but the fruiting performance of some 



