28 BULLETIN 722, U. S. DEPARTMENT OF AGRICULTURE. 
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 11 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. 
