28 THE "bluing" and the "ri:d hot" of the pine. 



cellulose goes on. large numbers of fibers separate in a body from the 

 adjoining- ones, often along the lines of medullary rays, and the spaces 

 so formed are rapidly filled with fungus threads, giving rise to the 

 white sheets already spoken of. (See PL X. fig. '2.) 



CONDITIONS FAVORIXG THK DEVELOPMENT OF THE '" RED-ROT " FUNGUS. 



One of the most important factors which influences the development 

 of the ''red-rot*' funo-us. and one which holds for all fungi, is water. 



O . CD 



If the trees in the Black Hills were dry, the red rot would make but 

 slight progress. At the time when the attack takes place the trees are 

 full of water, especially the tops, for these have lived longer than the 

 butts of the trees, and water was pumped into them long after the 

 lower parts of the trees were dead. Tlie top. therefore, is the most 

 favorable point for the ''red-rot*- fungus, and it is there that it is 

 found developing most rapidly. From the top the fungus may grow 

 down, so as to afiect the lower part of the trunk, but as this has been 

 drying continuously since the beetle attack one will find that it is veiy 

 rare for those parts of the trunk situated at points 5 to 3< ' feet from the 

 ground to be seriously injured by this fungus in the first years after 

 the death of the trees. This is an exceedingly important considera- 

 tion when the practical phase of this subject is taken into account. 



The relation of the water supply to the " red rot" is illustrated veiy 

 well in the large number of trees where the bark has died and peeled 

 off from one side of the tree. On PI. X, fig. '2. a photograph of such 

 a case is reproduced. The bark has fallen off' on the south and south- 

 west sides of the tree, but it still is attached to the opposite side. The 

 result of this peeling becomes evident very soon, for on that side the 

 wood dried ver}' rapidly, while on the other side the bark prevented 

 such evaporation. The wood remained moist, and here the '"red-rot" 

 fungus found a footing and conditions favorable for its growth. The 

 result was that in the course of some months the north and northeast 

 sides of that trunk were completeh' decaj'ed, while the opposite side 

 remained sound. A similar instance is shown in the largest section on 

 PI. VI, fig. 2: in this case at the base of the tree. 



Where the bull pine grows on hillsides not exposed to the sun or 

 wind, or where there is much undergrowth, one will frequently find 

 the '"red-rot" fungus entering the trees at the base before it attacks 

 the top. . This is likewise due to the fact that the water has not left the 

 trunk with suflicient rapidity to prevent the attack. 



FINAL STAGES AND FRUITING ORGANS. 



When the tops become rotted almost to the heart they become so 

 weak that thev are broken off' bv the first wind. In those sections of 



