102 
trate between tlie cells for three or more layers (Fig. 3), completely sur¬ 
rounding the discolored cell fragments that remain, probably because 
the fungus is not able to absorb them. In older specimens the fruit is 
not borne in distinct pustules, but the epidermis seems to be broken up 
into flakes and the basidia are borne uniformly or in tufts on the fruiting 
surface. In the course of from two days to a week after the first basidia 
and spores are formed the dark brown set® may be formed among them. 
They grow out from somewhat enlarged darker cells in the stroma, and 
are bluntly rounded at first, but become more acute as they grow older. 
They are frequently enlarged or present other irregularities somewhere 
along their course, especially near the tip (Fig. 1 a). The bases are 
a very dark brown, but the tips are usually nearly colorless. Uuder some 
conditions, especially in a moist atmosphere, the set® may bear spores 
at their tips. These spores seem to be somewhat smaller than those borne 
on the regular basidia, but in artificial cultures the two kinds are indis¬ 
tinguishable. At first the set® are few, but they increase in number 
with the age of the fungus, and in some sections the conclusion that 
the basidia themselves are being transformed into set® is almost irre¬ 
sistible. In older specimens the set® appear in large tufts and some¬ 
times branch. It is not infrequently the case that one seta arises from 
the lower end of another; a beginning of this may be seen in Fig. 1. 
The amount of stroma is also seen to increase with age, especially be¬ 
neath the set®, where it becomes very dark colored. In old speci¬ 
mens the set® are borne considerably above the basidia, so that the 
latter line the cavities between them (Fig. 1). The tufts of set® may 
even have the appearance of being pushed up and out of the way by the 
basidia and spores behind them. 
The spores are oblong, and usually have a vacuole in the center. 
Viewed separately under the microscope they are colorless, but in masses 
they form a salmon-pink powder which gives the color to the spots as al¬ 
ready described. They are successively abscised from colorless basidia, 
which vary greatly in length and may branch when kept excessively 
moist (Figs. 4-7). Usually the connection between the spore and the 
basidium becomes smaller until the spore is cutoff; but there are cases 
where the spore falls from the end of the basidium when the septum 
separating them is half as wide as the basidium itself, which appears 
truncate after the spore has fallen. The set® which have borne spores 
also often have a truncate appearance. 
The fungus retains its vitality under very adverse circumstances. 
Some specimens of diseased bolls were allowed to lie in the heated air 
of the laboratory for a month or more. The pink spore powder was 
then entirely washed from the surface, a piece cut out and soaked, and 
placed under a bell glass. In three days the surface again showed small 
masses of pink spores that had been produced since the fungus was 
put under the bell glass. 
An attempt was made to grow this fungus in a decoction of hollyhock 
agar-agar. This was only a partial success, for while spores and set® 
