A STUDY OF HEART-ROT IN WESTERN HEMLOCK. Mi 
formation. The swaying of the trees by the wind when the low 
temperature has set up a stress within the tissues of the lower trunk 
would cause the cracks to form at right angles to the swaying move- 
ment and in the root-spur hollows, where the least resistance to 
splitting was to be encountered. The swaying of the tree alone 
sets up varying forces of strain and rupture in the lower part of the 
tree, and when the tissues are contracted or prevented by low tem- 
peratures from adjusting themselves, a frost crack eventually occurs. 
Sporophores of fungi, if they develop at all, appear after a certain 
period has elapsed from the time of first infection. This period, up 
to the present time, has not been determined for most of the xyloph- 
ilous fungi, at least not for Hchinodontwum tinctorium. Such deter- 
mination would involve a considerable amount of careful inoculation 
work upon trees absolutely free from fungous infection, which in the 
case of wood-destroying fungi would extend over a period of several 
years. The relation which sporophores bear to the development of 
decay in the host and to the degree of infection can more easily be 
determined. A careful field study of the tree in question with 
reference to recording all possible data relating to the sporophores 
has developed several interesting facts. Little work has been done 
along this line tending to give actual figures as a basis for con- 
clusions. The data collected are grouped under the two parts of — 
Table V for the river-bottom and slope types, respectively. Under 
the heading ‘‘Position on tree,” the sporophores were grouped to 
indicate whether the northerly growing sporophores were more 
numerous than those growing on the southerly side of the tree. The 
remaining columns in Table V are self-explanatory with the excep- 
tion of the column headed ‘‘ Relative position along trunk.” This 
refers to the vertical position of the largest sporophore with respect 
to the other sporophores on the same tree. For example, tree 
No. 50 had a total of five sporophores, of which the third one from 
the ground was the largest. This condition was expressed by the 
figures 3-5, indicating that the position of the largest sporophore 
was in the center of the group. This method was used throughout, 
and the resulting figures were used to determine whether the largest 
sporophore was found more commonly in the center or toward either 
end of the group. 
The river-bottom type with reference to its sporophore data 
(Table V) is in general very similar to the slope type. Out of a 
total of 119 trees, 70 (59 per cent) were sporophore-bearing trees. 
On these 70 trees a total of 149 sporophores were found, of which 
131 (88 per cent) were living and 18 (12 per cent) were dead, giving 
an average of 1.8 live sporophores to a tree and 1 dead sporophore 
to every 4 trees. These figures show a much larger percentage 
