1882.] FUNGI INJURIOUS TO VEGETATION. 171 



most common ones being members of the fungus group. 3. A 

 class which, so far as I know, is due to neither of these two. A 

 group of true diseases, where the plants are "out of health" — a 

 real sickness, brought about by one or more of a multitude of dif- 

 ferent and often unknown causes. The leaves of the apple tree 

 are doubtless infested by a fungus, which has been known for a 

 long time, though it is not fully understood even now. It has 

 been stated that there are several stages in the life of the wheat 

 rust-plant, in one of which it is on the barberry. The fungus on 

 the apple leaf belongs to the same group, and is the "cluster-cup " 

 form of the species, resembling the "barberry state" of the wheat 

 rust. The cup is deeper, the neck extends much further above the 

 surface of the leaf, and is more finely fringed about the edges, but in 

 a general way a description of the one will answer for both. If 

 these " cluster-cups " upon the apple are but a form, or a single 

 stage of some fungus, the question naturally arises: on what plant 

 (or plants) does the other form (or do the other forms) appear ? 

 This question has been an interesting and diflBcult one for students 

 of these subjects; but it is generally considered that the "cedar- 

 apples " of the red cedar — those bright orange masses which ap- 

 pear in spring after a shower, or during a long rain, and are some- 

 times taken for the flower of the cedar, and frequently eaten by 

 children as the fruit — are caused by the same fungus, this be- 

 ing the last stages of the species. Not long ago I saw an apple 

 tree that was growing with its limbs interlocked with those of a 

 cedar, and on those limbs the fungus was unusually abundant; in 

 fact, the leaves were so covered that there was scarcely room for 

 another "cup," while the other trees of the orchard had only the 

 usual amount. The cedar tree was also more infested with the so- 

 called " apples " than others in the woods near by. Besides attack- 

 ing the leaves, and thereby injuring the fruit-producing power of 

 the tree, the fungus attacks the fruit itself. Prof. Wm. H. Buck- 

 out of the Pennsylvania Agricultural College gives an excellent 

 example that has recently come under his notice. 



To quote Prof. Buckout's remarks : "Mr. Washington Campbell, 

 of Linden Hall (Center Co., Pa.), brought me the leaves and fruit 

 of the apple locally known as the ' Pound ' (Fallawater of Down- 

 ing), upon both of which the ' cluster-cups ' were thickly scattered. 

 Those upon the fruit were in patches about the size of a small 

 coin, and most frequently found upon the 'eye.' Sometimes, how- 

 ever, they were upon the side, and unconnected with either the 



