1G2 EXPERIMENT STATION. [Jan. 



a great many investigators have been at work on it. Finally, 

 Prof. J. B. S. Norton in 1902 sncceeded in giving us its life 

 liistorj in full, having found the ascos])ore stage. Within the 

 United States, at least, the greatest damage is caused to the 

 stone fruits. 



Symptoms {on Fruit). — The first indications of the disease 

 on the fruit are Itrown spots of a leathery ajipearance, which 

 enlarge rapidly, and after the mycelium has become mature, the 

 conidiophores break through the epidermis and give to the spots 

 a downy, dirty, grayish-bro^vn color, due to the great quantity 

 of couidia produced by the fungus. The fruit then shrinks and 

 withers to a thin, tough pellicle. In this " mummied " condi- 

 tion it hangs on the trees over winter or falls to the ground, 

 where the fungus remains dormant until the right conditions of 

 moisture and temperature cause it to become active and attack 

 its host the following spring. The dormant or sclerotium form 

 of this fungus occurs where the '' mummied " fruit has laid on 

 the ground over winter, covered by a thin layer of soil. These 

 sclerotia give rise to apothecia, which are funnel-shaped, re- 

 sembling small toadstools. The asci line, the cup-shaped por- 

 tion of the apothecia and each ascus, contains eight ascospores. 

 So far as I know this has not been found by any of the Massa- 

 chusetts Experiment Station staff. The fungus will attack the 

 fruit at different stages of its growth, but it makes the greatest 

 headway on fruit that is almost mature. If the fruit has been 

 attacked by the curculio, or injured in any way, the fungus 

 readily takes advantage of the injury to get in its deadly work. 

 It might be said, however, that althongh it attacks the fruit 

 most readily where it has been injured, it will also attack the 

 ])erfect fruit should the humidity and the temperature of the 

 atmosphere be right. In the case of plums the fungus may 

 have been working for some time within the tissue without 

 being outwardly noticeable. This fact has put many shippers 

 to great disadvantage and caused them much loss. 



On Floivers. — The fungus usually first attacks the flowers 

 just after the petals fall, but it has been known to attack them 

 previous to that time. The first iuflication that the fungus is 

 present is a slight brown discoloration on some part of the 



