DISEASES OF TAXODIUM AND LIBOCEDRUS. 



within the diseased centers and grows between these 

 centers without affecting the intervening wood. This wood 

 can be utilized for many purposes even when much rotted, 

 and in neither case does the mycelium grow after the tree 

 has once been cut down. The two trees thus diseased, 

 both representatives of a race of trees the majority of 

 which are extinct, are closely related genetically, although 

 growing in different parts of the country. The two forms 

 of decay differ but slightly, and not more than might be 

 expected in two woods of different character. Taking those 

 facts into consideration, it appears probable that the two 

 diseases are caused by one and the same fungus, the fruiting 

 form of which has not yet been found. 



EXPLANATION OF PLATES ILLUSTRATING DISEASES OF 

 TAXODIUM AND LIBOCEDRUS. 



Plates 1, 2, plate 4, fig. 3, and the coloring of plate 3, 

 fig. 2, and plate 4, fig. 2, were prepared under my direction 

 by Miss Harriet P. Learned. 



Plate 1. 1, Branch of Taxodium distichum, showing early stage of 

 the pecky disease. The wood turns yellow in longitudinal lines (X$) 

 2, A block of Taxodium distichum cut from the heart of a tree several 

 hundred years old, showing advanced stage of peckiness. In a large 

 number of trees the rotted portion is more yellow than that shown in the 

 figure (XD. 



Plate 2. A block of Libocedrus decurrens showing advanced stage of 

 the pecky disease. The rotted wood has fallen out from the holes at the 

 tight of the figure leaving a smooth surface (XiV 



Plate 3. 1, Transection of pecky cypress wood. The section was 

 made so as to include some of the much rotted wood, seen at the bottom 

 of the figure, also some of the sound wood. It was stained with phloro- 

 glucin and HC1. The violet of the original section was somewhat more 

 marked than is the color in the figure. The portions staining violet indi- 

 cate wood which has not been affected by the fungus, those staining 

 yellow show where the coniferin elements have been extracted : ' m ' 

 medullary rays; *k' cell -walls from which the coniferin has been ex- 

 tracted ; * p ' normal cell-wall ; ' d ' primary lamella resisting the disinte- 

 grating factor longer than the secondary lamellae; <h' perforation of 

 cell-wall made by fungus hypha (magnification same as fig. 2) . 2, Tran- 



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