APPI,E DISEASES. 195 



No other means of reproduction than by conidia has been 

 observed either in culture or in nature. Smith did not find 

 the perfect stage of C. beyerinckii Oudem. although Vuillemin 

 (6) has described a species of Ascospora {A. beyerinckii Vuil.) 

 which he considered to be the perfect form of C. beyerinckii. 



Plioina inali Schulz. et Sacc. 



Another fungus which was isolated from leaf-spots from 

 several sources during the summer of 1908 has been studied in 

 some detail. This fungus did not occur with enough prom- 

 inence on the leaves to suggest that it caused the disease but 

 it was kept in culture for later study. The fungus did not fruit 

 in culture for several months, although it grew very readily. 

 In the fall of 1908, a fungus was isolated from decaying apples 

 which agreed in cultural characters with the one from leaf- 

 spot. 



Apples were inoculated October 31, 1908, with material from 

 a culture of the fungus from leaf-spot. Only a few days were 

 recjuired to prove that the fungus was able to produce a distinct 

 apple decay which .spread at about the same rate as the decay 

 caused by some of the well known apple decay fungi. In order 

 to prove that the fungus with which the apples were inoculated 

 was the cause of decay, plates were made for reisolation by 

 taking material from the decaying tissue with a sterilized 

 scalpel and transferring it to plates of agar. All the plates 

 produced pure cultures. 



Figure 22 shows the extent of the decay in an apple two 

 weeks after inoculation. Figure 23 is from the same apple cut 

 open and shows that it was almost half decayed at that time. 

 The condition of an apple 34 days after inoculation is shown 

 by Fig. 24. The apple is completely decayed, is somewhat 

 shrunken and wrinkled and lumicrous pycnidia as well as a 

 considerable auKnuit .of white mycelium are seen on the surface. 

 ]\ficroscopic examination showed that the pycnidia contained 

 large numbers of hyaline, one-celled spores, which were two 

 guttulate and measured 2.5-3 x 5.5-8 microns. Cultures were 

 made from this apple both by making dilution plates using 

 spores from a pycnidium and by transferring decayed tissue 

 from the inside of the apple. In both ways pure cultures were 

 secured and it was shown that the pycnidia belonged to the 



