166 



Mycologia 



2C), f. 5). This entire aggregation of spherical cells and append- 

 ages usually remains in union and functions as a spore. When 

 abundant, these sporodochia present to the eye the appearance of 

 a reddish-brown dust over the upper surface of the leaf {pi. 28, 

 f. i). The presence of the brown stromata may easily be known 

 at a distance of 10 to 20 feet by this characteristic appearance. 

 In most cases these sporodochia are found only on the upper sur- 

 face, but if the lower surface of a leaf happens to be turned over 

 for some time they will develop there also. This condition of 

 the fungus is common in the summer and fall. The sporodochia 

 were first noticed in the fall of 1905, and have been observed 

 since in great abundance every year. The supposed connection 

 of these sporodochia with the brown stromata was touched upon 

 in 1908 (15), but only recently has the connection between the 

 two been proved. The relation of the sporodochia to the spread 

 of the fungus is interesting. When mature, the sporodochium 

 with its accompanying appendages breaks off from the mycelium 

 and remains upon the surface, apparently held lightly by the 

 appendages. The inflated cells make it light, so that when once 

 detached it blows about easily, and on coming in contact with a 

 fairly rough surface it tends to hold fast to it. It seems probable 

 that the appendages may also serve to hold the sporodochia to 

 bodies of large insects that may drag them from one part of the 

 tree to another. 



Germination of Sporodochia 

 These Aegerita sporodochia when germinated in hanging-drop 

 cultures of sterile water and in 5 per cent, glucose solution, were 

 seen to produce hyphae {pi. 28, identical with those which 



compose the brown stromata on the whitefly larvae. When 

 germinating, the first hyphae grow out either from the sporo- 

 dochia or from the ends of the appendages. These branch rather 

 sparingly, but in a few days, in 5 per cent, glucose solution, form 

 a network by the intercrossing of the branches {pi. 28, f. 4). 



Inoculations of Whitefly Larvae 

 Four different attempts were made to inoculate larvae of white- 

 fly with these sporodochia, three of which were successful. One 



