28 lUTLLETIN 722, IT. S. DEPARTMENT OF ACRTCITLTURE. 



of live sporophores than those of the slope type. Almost all (96 

 per cent) of the largest were living, which was equally true of the 

 sporophores in general. The average height from the ground is 

 8.7 feet. The northwest to north-northeast grouping held 53 per 

 cent of the total sporophores, the southwest to south-southeast 

 grouping 27 per cent, the east 9 per cent, and the west 11 per cent. 

 Most of the sporophores are grouped on the northern aspect of the 

 trunks, with a smaller percentage on the southern. Upon dividing 

 the sporophores into groups corresponding to the eight principal 

 points of the compass, it was found that most of them (23 per cent) 

 were on the northwest side, the next largest on the south (18 per 

 cent), and the smallest number on the southeast (3 per cent). 



The figures in Table V, river-bottom type, relative to the number 

 of sporophores are plotted in figure 1 1 and show the relation between 

 the degrees of infection and the number of sporophores. To avoid 

 the awkwardness of using such an expression as ''1.3 sporophores" 

 in the diagrams, it was thought proper to term this factor ''Number 

 of sporophores per 10 trees" and use the same figures after multi- 

 plying each by 10. This does not alter the comparative value of 

 the figures. These data and the pathographs indicate how the 

 increase in the number of sporophores keeps pace with the increase 

 in the degree of infection. 



In the southwestern-slope type (Table V), out of a total of 81 

 trees 54 (67 per cent) bore sporophores in varying numbers. These 

 54 trees carried a total of 210 sporophores, of which 141. (67 per 

 cent) were alive and 69 (33 per cent) were dead, giving an average of 

 2.6 live and 1.2 dead sporophores per sporophore-bearing tree. 

 More than half (60 per cent) of the largest were living. These data 

 indicate that the number of sporophores increases with increased 

 age and with increase in the degree of infection as expressed by the rot 

 percentage. This holds true for all the age classes except the oldest, 

 which is found to have a smaller total number of sporophores and a 

 smaller number per 10 trees than the 161 to 200 age class. This 

 may be due to the fact that the maximum sporophore production 

 has been reached in the 161 to 200 age class and to the further fact 

 that on old trees the older sporophores are often found to have 

 dropped to the ground. An average of all the figures relative to 

 the vertical position of the largest sporophore gave a figure which 

 placed it at or very near the middle point. This would seem to 

 indicate that the decay spreads more or less in both directions up 

 and down the trunk from the point of original infection; consequently 

 the sporophores are produced on either side of the largest as the 

 decay progresses. This is, of course, not true in every case, but the 

 average condition is found to be such. 



