296 MISSOURI STATE HORTICULTURAL SOCIETY. 



which imparts a curious appearance. A portion of the cup is buried in 

 the tissue of tlie leaf, while the open end protrudes through the rup- 

 tured epidermis of the host. The cups contains the spores or repro- 

 ductive bodies of the fungus. The spores are orange colored, globular 

 bodies and are formed in vertical chains or rows. When mature, the 

 slightest touch destroys the bead-like arrangement of the spores and 

 they escape from the cup. The spores are less than one-three-hund- 

 reth of an inch in diameter, and being very light, they are easily wafted 

 from place to ])lace by the wind and other agents. 



The spots on the apple leaf usually appear about the middle of 

 May or the first of June and the first mature reproductive bodies 

 escape about the first of July. One would naturally suppose that 

 the spores of this fungus would germinate on the apple and ulti- 

 mately produce the same kind of spots from which they were derived. 

 But as a matter of fact it is known that when the spores fall upon 

 apple leaves they produce no effect. If, however, some of the spores 

 fall upon the young branches of the common red cedar {Juniperius 

 Virginiana) and the proper conditions of moisture and temperature are 

 present they germinate, and give rise to a fungus on the red cedar, 

 differing in many respects from the form on the apple. When the spores 

 from the apple leaf germinate upon red cedar, a mass of threads 

 {mycelium) is produced in the tissues near where the spores germinated. 

 The mycelium continues growing through the summer months and 

 ultimately i)roduce8 globular, or kidney-shaped knots on the young 

 branches of the host. 



During the summer and winter months the knots remain hard and 

 wart-like, and show very little structure. The globular swelling on the 

 young branches of the red cedar, are commonly known as cedar 

 apples, and if you will examine one of them you will find a number of 

 spots on the surface. Early in spring, especially during damp weather, 

 long cylindrical masses of a jelly-hke substance protrude from the 

 spots mentioned above. These masses are frequently an inch in length. 

 Usually a number of the cylindrical masses escape from each swelling, 

 and the are usually aggregated in a somewhat globular tuft. 



The spores or reproductive bodies of this fungus are imbedded in 

 the jelly-like masses, and are supported on long, slender stalks or pedi- 

 cals. The spores are two-celled, generally constricted at the partition, 

 and vary in size and shape. They are usually about one three-hun- 

 dreths of an inch in diameter, and one-hundredth of an inch long. Like 

 the masses of jelly, the spores ard colored bright yellow. Doubtless 



