2 Brooks: The Fruit Spot of apples 



media, the fungus began its growth in the bottom and on the 

 sides of the vessel. After four or five days the entire surface that 

 was under water was thickly dotted with minute colonies. (This was 

 not true of the sides of Erlenmeyer flasks nor of the upper wall of 

 a slanting test-tube.) The number of colonies was dependent upon 

 the amount of surface and the number of spores introduced rather 

 than upon the quantity of solution. These colonies soon developed 

 into hemispherical gelatinous masses that could not be crushed when 

 placed on a slide under a cover-glass because of the readiness with 

 which they slid from between the glass surfaces (plate .31, figure 



A microscopic study of the material showed that its gelatinous 

 nature was due to the fact that the hyphae upon coming in con- 

 tact with each other became fastened together. This attachment 

 often extended to a breaking down of the walls between the hy- 

 phae and the merging of two cells into one. The result was a 

 peculiarly anastomosed fungous mass. Spores were most abun- 

 dant on the surface of these masses but were produced through- 

 out the colony. They were hyaline, consisted of from one 

 to five cells and were from 2 to 3 ft wide by 20 to 60 ft long- 

 The hyphae were septate and about 3 ft in diameter. ^ 

 spores were cut off from the tip of knob-like projections on 

 side of the hypha as described below for the agar cultures, 

 few days later these colonies would go to pieces and a g 

 would soon begin to form on the surface of the liquid, 

 growth was light-colored at first and of uniform texture throU ^ 

 out, but later had a very definite zonation both as to color a 



the 

 A 



PLATE 33. FIGURE 2). O 



of 



hyaline conidiophores arising from a zone of vertical r 

 phae that formed the upper margin of a dense black s 

 layer. The hyphae of this stroma were thick-walled, abun an^ 

 septate, and from 3 to 6 ft in diameter. Beneath it w 

 compact layer composed of a mixture of coarse and nn 

 In some cases there was a series of such zones as ^ 



been described. This may have been due to the fact t a^ 

 liquid had been left on the top of the stroma when examl ^ re it 

 of the flask were made. In a five months old flask c 

 was noticed that numerous, somewhat hemisphenca e 



had dpvplnnprl nn the- «iit-far<* nf thp stroma I PLATE 33» 



