May 1904] 
Variability of Dictyophora 
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the dimensions of twenty plants including specimens showing the 
extreme variations in all of the characteristic parts of the plant. 
The specimens are arranged in the table according to height. 
It will be seen that the extremely tall and extremely short 
specimens are not so numerous in the above table as are the more 
nearly average ones. As these are about equally scarce also in 
nature the above averages may safely be taken as approximately 
correct for all the specimens found during the season. 
There is a fairly complete series from the shortest (5.6 cm.) 
to the tallest (21.2 cm.). Careful observations were made to de¬ 
termine, as nearly as possible, what conditions might be respon¬ 
sible for the height of the specimen. It was found that without 
exception the tall plants were solitary, were taken from sod, and, 
in almost every case, were in a fairly shaded, moist locality. 
Numbers 1 to 6 of the table, and many others, were found so 
located. The smaller specimens were found where the plants 
occurred in large clusters and were often taken after several 
plants in the cluster had matured. When a plant in the egg stage 
was found on a substratum, such as the mulch already mentioned, 
that readily became dry, it could be predicted with certainty that 
the resulting fungus would be small. Very immature eggs (J to 
f size) were often separated from their mycelial connections and 
taken into the greenhouse. These often decayed. A good share 
of them, however, developed after several days producing very 
small specimens. This indicates that food and moisture, to¬ 
gether with the habit of growing singly or in clusters are im¬ 
portant factors in determining size. 
The volvae varied in size from 5.5 x 6 cm. to 2.4 x 3 cm. 
Where the eggs were in large groups they were often flattened 
against each other. A peculiar lobing was often caused in this 
way and also by foreign objects lying in contact with the egg. 
Eggs lying free in sod were spherical and smooth. The color of 
the eggs varied from white to pink or dirty brown. 
The size and shape of the pileus was as variable as the other 
characteristics. The taller plants in general had the larger pilei. 
The shape varied from a broadly campanulate pileus, 2.7 cm. 
high by 3.7 wide at the lower margin in No. 16, to the tall conical 
pileus 4.2 cm. high by 2.6 in diameter at the base as in No. 11. 
There is no correlation between the shape of the pileus and the 
size and structure of the other parts. Some very tall specimens 
had campanulate pilei while others had the conical form, the 
same was true of the small specimens. The outer surface was 
always conspicuously reticulated, the edge of the ridges being 
acute and toothed. The ridges always extended to the pore at 
the apex. The pits enclosed by the ridges were in general deeper 
midway between the apex and the margin of the pileus and often 
became elongated in the vertical direction near the margin. 
