148 
Mycologia 
walls, uniform capillitum with the usual violaceous rough spores, 
but unlike anything in the P. nephroidewm group. Other cal- 
careous genera are equally represented : there are about eight 
didymiums, four or five didermas, etc. 
Mucilago spongiosa (Leys) Morg. in the forests about Mt. 
Rainier is not at all uncommon. Its flecks of spume sometimes 
deck the stems and twigs of living plants all along a water- 
course. The light calcareous foam blows away as soon as dry, 
and leaves a curious dendritic, strangely intricate, grayish fructi- 
fication quite confirming Rostafinski’s figure 175. I11 Colorado, 
on the other hand, the same species retains its limey covering, 
shows almost no internal structure, and is almost as firm as the 
substratum, justifying Professor Sturgis when he writes var. 
solida. 
To nearly all the Colorado forms so far discussed, one remark 
applies : they are peculiar. Even where representing species 
widely known and studied, the Rocky Mountain gatherings would 
nearly all be subject of remark no sooner seen. Furthermore the 
peculiarity is, I believe, in many cases referable to the abrupt 
alternation in Colorado climate. Plasmodia called into being by 
the melting snows of early summer are often checked in complete 
development by the dry atmosphere suddenly encountered as they 
rise to fruit, and abnormality is the result. The most normal pre- 
sentations I have from Colorado are of those species which habit- 
ually fruit in less exposed positions, as on the lower side of stems, 
logs or heaps of mouldering vegetation. Such species are Bad- 
liamia utricularis (Bull.) R. ; Comatricha nigra (Pers.) Schr. 
The Fuligo species cited are worthy of further notice. It is of 
course observed that the spores in the three more closely related 
forms are singularly graded in size ; thus — F. septica, 6-7 /* ; F. 
media, 10-12 n; and F. megaspora, 18-20 n- 
Knowing what we do, by the researches of Harper, concerning 
the cytology of Fuligo, this correlation in size is very suggestive. 
Professor Harper has shown that the uninuclear spore is the 
issue of a peculiar plasmodical cleavage, whose progress in a 
given case may be arrested almost anywhere ; so that we might 
have reproductive bodies by this process ranging from large scle- 
rotia to the smallest spores. 
