LAECH MISTLETOE. 21 



The trees were selected from a comparatively small area after the 

 preliminary survey had shown the nature of the deterioration to be 

 universal and similar over large areas of the same type of stand. 

 Although the numerical basis for the figures in the table is very 

 meager, interesting results are shown, which fully justify the arrange- 

 ment. In the absence of suitable volume-table studies of the normal 

 growth of the same age class for the region, the arrangement of the 

 table is based entirely on the trees felled for study. An increasing 

 degree of infection is indicated by the larger number of cross marks 

 emploj^ed (columns 14 and 40). Selecting trees of the same age, the 

 study of the table may proceed as follows: Trees Nos. 42 and 27 

 are of the same age. The infection of N.o. 42 is xx ; of No. 27, 0. By 

 consulting column 27 the average width of sapwood for tree No. 42 

 is found to be 0.53 inch, and column 28 shows that the sapwood con- 

 sists ofsan average of 16 rings; tree No. 27 has an average width of 

 sapwood of 0.9 inch, with an average of 21.3 rings. Tree No. 42 

 showed a present period of suppression of 20 rings (column 30), the 

 combined width of which is 0.5 inch (column 29) ; tree No. 27 has 

 no present suppression and is marked in the table. The condition 

 of the sapwood, sound for both trees (column 31), indicates the ab- 

 sence of secondary causes of deterioration, as does in like manner the 

 column (32) on the condition of the heartwood. Referring to other 

 columns, tree No. 42 is shown to have a total height of 53 feet (col- 

 umn 33), a full volume of 25 feet, board measure (column 35), a 

 breast-high diameter of 5 inches (column 37), and is dominant (col- 

 umn 36) ; tree No. 27, on the other hand, has a total height of 60 feet, 

 a full volume of 40 feet, board measure, a breast-high diameter of 

 6.65 inches, and is sufficiently overtopped and crowned by its neigh- 

 bors to be marked intermediate. 



The fact that the infected tree stood fairly in the open, with no 

 deteriorating agents other than mistletoe associated with it, leaves 

 .small room for doubt that the tree was suppressed by the parasite 

 upon it. Table II shows that tree No. 42 has seven branch brooms 

 (column 8), with an average weight of 3 pounds per broom (column 

 11) on and above the average weight of the normal branch, which 

 i- -i pounds (column 10). 



The efl'ects of the mistletoe on its host are further shown by the 

 differences in tin- diameters of branches supporting brooms and those 

 not so encumbered (columns 12 and L3). The analysis of these trees 

 showed that both individual- started equally, but the measurements 

 and study of all cross sections showed plainly a retarded growth 

 during the last few years of life except at (lie slump, (lie section 

 pa sing through burl tissues (column 40). The age (if (lie tree can 

 Hi t beheld responsible for the falling off in increment. A compari- 

 son of the iiiea-urcinents taken at the various cross sections and at 



