206 Mycological Bulletin No. 52 [Vol. IV 



Ae-cid'-t-um, or Cluster-cups. — As already explained this represents 

 a stage, usually marked as "I," of a Black Rust. The second or so-called 

 Red-ru.st is mdicated by 'TI" and the third stage or Black-rust is num- 

 bered "III." The remarkable thing about an Aecidium is that its spores do 

 not grow on the host on which they are produced but often on germinating 

 enter a grass or sedge or some other host and there the stages "H" and 

 "III" inifold. This was rot at first known, but each Aecidium was sup- 

 posed to be a complete plant and of course each received a scientific name. 

 It was a German botanist, DeBary, who nearly a half century ago proved 

 by culture in his laboratory^ that the aecidium on Barberry was the first 

 stage of one of the Red and Black Rusts that grow on wheat. Later ex- 

 periments have shown the connection of many of our common Yellow 

 Cluster-Cups with Red and Black Rusts on various hosts — yet the life 

 cycle of very many of our common species remain to be worked out. 



"QUOTATION PAGE." 

 {Continued from page 202) 



it could be predicted with certainty that the resulting fungus would be 

 small. Very immature eggs (^ to 54 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 pro- 

 ducing ven,' small specimens. This indicates that food and moisture, 

 together with the habit of growing singly or in clusters are important fac- 

 tors in determining size. 



The volvae varied in size from 5.5 x 6 cm. to 2.4 x .3 cm. Where the 

 eggs v/ere 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 eggs. Eggs lying free in sod were spherical and 

 smooth. The color of the egg.s varied from white to pink or dirty brown. 



The size and .shape of the pileus was as variable as the other charac- 

 teristics, the taller plants in general had the larger pilei. The shape 

 varied from a broadly campanulatc 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. * * * 



There is no other part of the whole plant that shows as great variation 

 in both size and structure as does the veil. The veil of a given specimen 

 may vary with the age of the specimen when collected, or with the sur- 

 rounding conditions. It was often observed that the veil expanded after 

 the stipe had fully elongated. In other specimens the expansion of the veil 

 was more rapid than the elongation of the stipe. In such cases the veil 

 protruded I'rom between the pileus and the volva as a large fold, which 

 inter straightens out and hangs free when the stipe is fully extended. 

 When a specimen bad been exposed to a dry atmosphere for a simrt time 

 the veil became much shrunken. The measurements given in the table were 

 taken from specimens gathered at about ten o'clock in the forenoon. Care 

 was taken to meastire the length of the veil when it was most fully ex- 

 panded. While the outside conditions in which the plant is found, mav 

 modify the dimensions of the veil, there is no doubt that the actual anK>unt 

 of material which enters into it is as variable as any other feature of the 

 plant.." f.'\. H. Christman, Journal of Mycology]. 



