8 BULLETIN 116, U. S. DEPARTMENT OF AGRICULTURE. 
in their wideness of distribution. The fact that 938 trees bearing 
fruiting bodies of the fungus were found within a certain area is of 
no special significance unless we note that they were found in about 
thirty different localities which are scattered well over that entire 
area of thousands of square miles. Then we perceive that it is 
inevitable that the disease will become established in one or more of 
those localities unless efficient control measures are taken and faith- 
fully continued until the disease is eradicated. As already indicated, 
this is not being done everywhere. 
Table II. — Results of inspections of 80 lots of infected white-pine trees. 
No. 
Item. 
Lots. 
Trees found bearing fruiting bodies in 1910 and not afterwards 
Trees found bearing fruiting bodies in 1911 and not in 1910 or 1912 
Trees found bearing fruiting bodies one year and also each year afterwards 
Tree. - bearing fruiting bodies not found at first, but which were discovered later. 
Diseased trees found at firs t, but no i in later years 
Diseased trees found continuously 
Diseased trees found irregularly (does not include those in item 5) 
Items 1 and 2 show that in one-fifth of the lots the inspector appar- 
ently removed all the trees bearing fruiting bodies of the fungus in a 
single year, but in every such case trees were found thereafter which 
were diseased, but did not bear the spores of the fungus. In a single 
instance only, all of the diseased trees were apparently removed by the 
first inspection. Our experience to date decidedly discourages the 
idea that a single inspection is efficient in eradicating this disease. 
Item 5 apparently contradicts this statement, but these lots may 
easily have been cases where the inspector took everything showing 
any abnormality and reported it as suspicious, when the disease was 
really absent. 
In a previous paper x the writer mentioned the apparent effect of 
cool weather in regulating the formation of telia of Cronartium ribicola 
in the greenhouse at Washington. This experience has been repeated 
the present season. Apparently, farther north, where the nights are 
relatively cool, this inhibition does not occur, as telia were found in 
northern Vermont on July 23. 
In a recent publication, 2 which received limited distribution, the 
writer showed the inefficiency of inspection, except as a temporary 
expedient, in trying to eradicate this disease. The total destruction 
of infected lots of white pines was urged as being the only safe course. 
This means a considerable present loss, which, however, will be very 
slight when compared with the loss that will result if the blister rust 
is allowed to become established and to spread. 
1 Spaulding, Perley. Notes upon Cronartium ribicola. In Science, n. s., v. 35, no. 891, p. 146-147. 1912. 
2 Spaulding, Perley. The present status of the white-pine blister rust. In TJ. S. Dept. Agr., Bur. Plant 
Indus. Circ. 129, p. 9-20, 6 fig. 1913. 
O 
WASHINGTON : GOVERNMENT PRINTING OFFICE : 1914 
