Stevens : Polystictus versicolor 



265 



decayed stumps which bore six or more good sized sprouts, every 

 sprout showed a considerable decayed area. In the entire eighty 

 acres, however, only three sprouts were found which bore sporo- 

 phores. 



There can be little question that the decayed sprouts were in- 

 fected from the stump. In the great majority of cases, the 

 sprouts showed no injury through which the fungus might have 

 entered, and the decayed area was always largest at the base of 

 the sprout. Moreover, no such decayed areas were found in 

 sprouts from sound stumps. The decayed area generally occu- 

 pied the center of the sprout and extended up from the base 

 for some distance, usually less than two feet and very rarely as 

 much as three. Figs, i and 2 show two sections through an 

 unusually large sprout from a stump which bore a large number 

 of sporophores. The section shown in fig. 2 was cut about six 

 inches above the stump and that in fig. i two feet above the 

 stump. These figures show that the growth of the sprout had 

 been very rapid, much more rapid in this case than in the ma- 

 jority of the sprouts from sound stumps, and that the action of 

 the fungus was limited thus far to a comparatively small portion 

 of the sprout. How rapid the further progress of the fungus 

 may be cannot, of course, be determined at present, but it is cer- 

 tain that this fungus frequently spreads much more than two 

 feet a year in living catalpa trees. (See 8, p. 53.) 



Why decay had not progressed further is a most interesting 

 question. There can be no doubt that the fungus both in the 

 stump and in the sprout was alive and in a vigorous condition at 

 the time the trees were examined. Pieces of the rotten wood 

 placed in a moist chamber showed in a few days a dense growth 

 of characteristic mycelium. Moreover, it is entirely probable 

 that the stumps which produced the rotten sprouts were them- 

 selves infected before the trees were cut. Many of the stumps 

 certainly were affected when the plantation was cut over and it 

 is difiicult to suppose that the fungus died in these stumps and 

 that they or other stumps were infected later. Infection of 

 sound catalpa wood does not easily occur and the stumps in ques- 

 tion were most rotten at the center, exactly the condition found 

 in the stumps of badly rotted trees. 



