DESCRIPTION OF PLATES. 
Puate I. ( Frontispiece.) Three apples affected with bitter-rot and three mummies 
which presumably furnished the infection. The twigs with these fruits and 
mummies attached were cut from one of the unsprayed trees in the experimental 
orchard on July 10, and the photograph was made two days later. 
Piate II. The microscopic characters of the bitter-rot fungus ( Glomerella rufomacu- 
lans (Berk.) Spaulding & von Schrenk): 1.—Five asci, each containing eight 
ascospores; also one probably immature ascus. 900. 2.—A group of free 
ascospores. 900. 3.—A group of ascospores germinating in a drop of water. 
«900. 4.—Spore-bearing hyphe springing from a mycelium growing in nutrient 
agar: a, the mycelium giving rise to the fertile hyphz; 6, a group of conidia, 
or summer spores, newly born. 600. 5.—A group of germinating conidia. 
740. 6.—A section through a pustule showing the ruptured skin of the apple, 
the spore-bearing hyphe, and the free conidia. 200. 
Puate III. Fig. 1.—The crop picked from one tree of Plot 3, showing 334 bushels of 
sound fruit on the left and 1} bushels of rotten fruit on the right. Fig. 2.—Fruit 
from an untreated tree (Check A). The only sound apple from the tree is 
shown on top of the basket. ? 
Puate IY. Fig. 1.—Crop picked from one of the trees in Plot 6, showing 39 bushels 
of sound fruit and less than a peck of rotten fruit in the half-bushel measure on 
top of the pile. The fruit still shows a coating of Bordeaux mixture. Fig. 2.— 
The crop from an unsprayed tree (Check D), showing only two sound apples, 
which are placed on a board on top of the heap of rotten fruit. 
Puate V. Fig. 1.—Fruit from one of the trees in Plot 1, showing 13} bushels of 
bitter-rot apples on the right, and 10 bushels of sound apples on the left; treat- 
ment too early for best results. Fig. 2.—The fruit from Plot 12, showing 12 
bushels of sound apples on the right, and 12? bushels of rotten fruit on the left; 
treatment too late to save the crop. 
Piate VI. Fig. 1.—A yellow Newtown apple badly affected with bitter-rot, and 
another recently mummified by the fungus. The specimen designated A shows 
a typical case of bitter-rot on a Yellow Newtown apple. The fruit was taken 
from the tree in this condition. The apple marked B has been recently mum- 
mified by bitter-rot, the entire fruit having become involved in decay. Fig. 2.— 
Apples harvested from one tree in Plot 16, showing 283 bushels of sound fruit 
above and to the left, and 15 bushels of rotten fruit in and near the baskets. 
Puate VII. An unsprayed tree (Check A) with most of its crop on the ground at 
picking time, illustrating the destructive work of the bitter-rot. 
Puate VIII. Fig. 1.—The platform and equipment used in preparing Bordeaux mix- 
ture; also showing the spray tank receiving a supply of Bordeaux mixture. 
Fig. 2.—The spraying outfit in operation. 
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