408 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 4 



that, in general, moisture is under pressure 

 throughout the heartwood of such an 

 affected tree. However, in a few cases he 

 found pressure to be present only in isolat- 

 ed sections of the heartwood. May (1942) 

 showed that bleeding or fluxing from the 

 heartwood of elms affected with wetwood 

 was independent of sap flow in the sap- 

 wood. He considered slime flux to be one 

 of the manifestations of wetwood. Cran- 

 dall (1943), working with winter-injured 

 Platanus acerifolia Willd. in 1934, found 

 a bacterial infection to be present in wet- 

 wood-affected trunk wood. He suggested 

 that the frost cracks that were present in 

 the trees affected with wetwood had 

 developed during periods of low tempera- 

 ture. The affected trees fluxed freely 

 through these cracks. Large (1944) 

 described a flux of tung tree as alcoholic 

 flux or white slime flux and stated that 

 the disease was confined to the cambial 

 region. He found bacteria and an Actino- 

 mycete-like fungus associated with this 

 type of flux. 



Most of the work on slime flux before 

 1935 was concerned mainly with the 

 visible manifestations of the disease on 

 the outside of trees. Ludwig (1886, 1888, 

 1890) described alcoholic flux or white 

 slime flux of oak, birch, poplar and maple, 

 and brown slime flux of apple, elm, birch, 

 horse chestnut, poplar and oak. He stated 

 that in brown slime flux the sap or slime 

 formed in the wood and broke through 

 the bark, and both the bark and wood 

 soon decayed. He associated Endoniyces 

 magnusii Ludw. with white slime flux, and 

 Micrococcus dendroporthos Ludw. with 

 brown slime flux. 



Following Ludwig's early work, slime 

 flux was investigated by Hansen (1889) 

 in Denmark, by Holtz (1901) and Stautz 

 (1931) in Germany, by Massee (1897, 

 1907) and Ogilvie (1924) in England, 

 and by Stone (1916) and Cook (1918) in 

 the United States. These investigators, 

 with the exception of Ogilvie (1924), be- 

 lieved that slime flux was caused by para- 

 sitic organisms. Massee (1897) produced 

 slime flux of apple and plum trees by 

 inoculating them with Micrococcus den- 

 droporthos hudw. Stautz (1931) pointed 

 out that no fungus hyphae were found in 

 affected wood but that bacteria were pres- 

 ent in drops of the sap. Tubeuf & Smith 

 (1897), Ward (1901) and Ogilvie 



(1924) believed that slime flux was not a 

 parasitic disease but an abnormal physio- 

 logical bleeding associated with normal or 

 abnormal pressures in the tree. 



Guba (1934, 1942), after reviewing 

 the literature, concluded that slime flux 

 was not a parasitic disease but that it 

 developed because of artificial environ- 

 ment and other mechanical or physiologi- 

 cal conditions. 



Hosts and Distribution 



In Illinois, wetwood has been found in 

 American elm, Ulnius americana L., in- 

 cluding the varieties Moline and Little- 

 ford, slippery elm, Ulnius fulva Michx., 

 English elm, Ulnius procera Salisb., and 

 Siberian elm, Ulrnus pmnila L. Trees 

 affected with this disease have been found 

 in 40 towns and 21 counties, as follows: 

 Quincy in Adams County ; Champaign and 



Fig. 1.— The black dots indicate the location 

 of towns in which wetwood-affected elms have 

 been found. 



