12 



heated to 160 degrees Centigrade or above in a hot air oven for 

 at least fifteen minutes. Before pouring the plates, the plugs 

 of the tubes were flamed, and also the ends of the tubes. The 

 pouring was done in a steamed room. 



Before any cultures were made from the tissue of the 

 apples the surface, which had been washed in water, and dried 

 with a clean towel, was wiped with sterilized cotton saturated 

 with absolute alcohol. The needles wei-e flamed before the iso- 

 lations were made. 



The F ungus 



As is shown in Table I, all but two of the isolations 

 attempted gave Alternaria. The cultures were all alike and 

 originated from the point where the needle was put in the agar. 

 From the number of isolations and the uniformity of the results 

 there would seem to be little doubt that this is the organism 

 which causes the spot, although inoculations on healthy apples 

 did not produce the same spot. It is probable that in the or- 

 chard the fungus gains entrance while the fruit is young, and 

 develops more or less with it. In the laboratory no results 

 were obtained without breaking the skin, and when the inocula- 

 tions were made under the surface a soft rot was produced with- 

 out any darkening of the skin of the fruit. Perhaps the mature 

 condition of the fruit on which inoculations were made allowed 



the rot to be soft. 



The Alternaria causing this spot is not morphologicallj 

 different from many other Alternarias which grow on a great 

 many hosts. Mr. Elliott of this laboratory determined it as 



