60 THE NORTH AMERICAN SLIME-MOULDS 



calcareous, the lime-knots rounded, angular ; spore-mass brown, spores 

 clear violaceous-brown, 6-7 yu,, distinctly warted. 



This delicate, inconspicuous species is well defined by the charac- 

 ters given. It occurs not rarely on richly manured ground, in 

 meadows, lawns, or even on the open prairie. The Plasmodium may 

 form rings several inches in diameter, scattered here and there over 

 a surface several square feet in extent, in fruit ascending the blades 

 of grass, completely covering these with the crowded sporangia. The 

 color of the fruit is well described in the specific name; gray or 

 ashen gray. The spores are very distinctly papillate ; in some speci- 

 mens, however, almost smooth; in few instances, rough. 



Common. New England west to the Black Hills and Pacific 

 coast. Cosmopolitan. 



The present species well illustrates the difficulty confronting the 

 author of to-day who, discussing a group of microscopic organisms, 

 would fain use the nomenclature of his predecessors, honored, but 

 equipped with insufficient lenses. Here is a species reported common 

 in Europe, observed by every mycologist there, from Micheli down, 

 and yet awaiting adequate description until Rostafinski in his great 

 book, gives the results of microscopic analysis. We are now really 

 dealing with P. cinereum Rost; P. cinereum Batsch is a compliment 

 to certain rather clever water-color drawings. 



Rostafinski gives a long list of synonyms, none, it is believed, rep- 

 resent American forms; and without taking careful thought, surely 

 no one would rudely disturb such honorable interment ; but, in his 

 description the range of spore-measurement, 7-13.3 fx, gives us pause, 

 and raises the suspicion that possibly, in one case or another, the 

 sepulture were perhaps premature. The range is too great ! Per- 

 haps, in the series offered in confirmation, small-spored forms repre- 

 sent one species, large-spored, something else? 



European students may decide this at their leisure. But Rosta- 

 finski having, not without much labor, practically completed his 

 review of the physaroid forms had almost finished the last genus 

 Badhamia, when his mind perhaps returned, no doubt with some 

 lingering misgivings, to the thirteenth species in his physarum list. 

 There were there, he recalled, some large-spored specimens which 



