Of course no botanist would confound the fructification of the _Trametes_ with that of the _Agaricus_; but the fructifications of such fungi only appear at certain seasons, and that of _Trametes radiciperda_ may be underground, and it is important to be able to distinguish such forms in the absence of the fructifications. The external symptoms of the disease, where young trees are concerned, are similar in both cases. In a plantation at Freising, in Bavaria, Prof. Hartig showed me young Weymouth pines (_P. Strobus_) attacked and killed by _Agaricus melleus_. The leaves turn pale and yellow, and the lower part of the stem--the so-called "collar"--begins to die and rot, the cortex above still looking healthy. So far the symptoms might be those due to the destructive action of other forms of tree-killing fungi. On uprooting a young pine, killed or badly attacked by the agaric, the roots are found to be matted together with a ball of earth permeated by the resin which has flowed out; this is very pronounced in the case of some pines, less so in others. On lifting up the scales of the bark, there will be found, not the silky white, delicate mycelium of the _Trametes_, but probably the dark cord-like rhizomorphs; there may also be flat white rhizomorphs in the young stages, but they are easily distinguished. These dark rhizomorphs may also be found spreading around into the soil from the roots, and they look so much like thin roots indeed that we can at once understand their name--rhizomorph. The presence of the rhizomorphs and (in the case of the resinous pines) the outflow of resin and sticking together of soil and roots are good distinctive features. No less evident are the differences to be found on examining the diseased timber, as exemplified by Prof. Hartig's magnificent specimens. The wood attacked assumes brown and bright yellow colors, and is marked by sharp brown or nearly black lines, bounding areas of one color and separating them from areas of another color. In some cases the yellow color is quite bright--canary yellow, or nearly so. The white areas scattered in this yellow matrix have no black specks in them, and can thus be distinguished from those due to the _Trametes_. In advanced stages the purple-black rhizomorphs will be found in the soft, spongy wood.