THE EARTH-INHABITING SPECIES OF 
ASCOBOLUS 
Fred J. Seaver 
(With Plate 184, Containing 8 Figures) 
Most of the species of the genus Ascobolus, which genus is 
characterized by the beautiful violet color of the spores, occur on 
the dung of animals of various kinds. Those forms which occur 
on other substrata are the exception rather than the rule. A few 
species occur on damp soil and these are the species which are 
treated in the present paper. 
Of the earth-inhibiting species of Ascobolus, one species, Asco- 
bolus carbonarius P. Karst, has been frequently collected in North 
America. In 1905 a second species was collected by the writer on 
damp soil along the banks of the Iowa River. This species was 
referred to Ascobolus viridis Curr. Since that time, the same 
species has been frequently collected on soil in New York State. 
Dodge in his morphological studies of the Ascobolaceae has noted 
the difference in the spores of the American and European speci- 
mens and has considered the American plants a possible variety of 
the European species. Comparative study of the two forms has 
convinced the writer that they represent two distinct species. The 
spores of the European plants are a third larger than those of the 
American and have an entirely different form as shown in the 
accompanying illustrations. The American plants are therefore 
redescribed below as Ascobolus geophilus. 
In August, 1914, a species of Ascobolus was collected on damp 
soil in woods near Yonkers, New York, which was taken to be 
Ascobolus viridis of American authors. The spores however 
were almost globose. At first, this was thought to be only an 
extreme variation of the common species. During September of 
the same year, similar plants were collected in considerable quan- 
tity on Staten Island where they grew on damp soil on the bank 
of a little pond. In all of these plants the mature spores would 
pass as globose. The young spores, however, are found to be 
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