NovEMBER 24, 1899.] 
for believing that the pines of Western Ne- 
braska are advancing eastward in places 
where the fires have been kept out,and where 
cattle are not allowed to destroy, and man 
is himself not too actively engaged in the 
work of forest destruction. I have made 
further observations on these western pines, 
and while I have no doubt that there are 
places where they are dying out, I am cer- 
tain that the general rule is that in west- 
ern Nebraska and portions, at least, of the 
Black Hills of South Dakota, they are tend- 
ing to advance, and that in many places 
they are actually advancing at a rate suf- 
ficiently rapid to be easily observed. 
I have been studying the tree areas of 
eastern Nebraska, also, and find evidence 
which is still more conclusive that they 
are advancing with a good deal of rapidity. 
My personal observations have been in 
so many localities that it is impossible to 
specify them in detail in this paper. They 
involve most of the counties in eastern Ne- 
braska. In practically every case where 
our travels up the streams, passing out to 
the side branches, to the little temporary 
rills which water the upper basins, the 
trees are of smaller size, and are much 
younger. It isa very rare occurence to find 
large trees near the upper end of a forest 
belt. I have seen a few of such cases, but 
their rarity is such that one is always sur- 
prised when they are found. The general 
rule is that near the upper limit of the tree 
area there are many shrubs and mingled 
with them many young trees no larger than 
those which under cultivation are known 
to be not more than fifteen to twenty years 
old. I may cite the following localities from 
my notes: (1) on the head waters of Oak 
Creek in Butler County, (2) headwaters of 
the Blue River in Seward and Hamilton 
counties, (3) headwaters of Weeping Water 
Creek, in Cass County, (4) along small 
streams in the Loup Valley, (5) along the 
small streams north of the Platte in Sarpy 
SCIENCE. 
769 
County, (6) headwaters of the little Ne- 
maha Creek in Nemaha County. 
I have asked some of the older settlers of 
the State in regard to this matter, and in- 
variably they tell me that the trees have 
advanced up the valleys. One man says: 
“in our neighborhood the native timber 
has crept up the water courses in some 
places a mile or more, and in other places it 
has widened out from near the stream 
banks,” and again in referring to a par- 
ticular spreading area he says: ‘in the 
places where we played in the ‘ buffalo wal- 
low’ twenty-five years ago, there are now 
many large trees.”’ 
Another says that in 1872 very few of the 
‘draws’ (i. e., ravines) had any trees in 
them, but now where fire is kept out all 
are filled with timber. He says that on 
his farm which was originally swept with 
prairie fires, ‘‘I had a ‘draw’ where water 
was half the year, in which in 1883 there 
were no trees of any kind, while now 
there are willow, cottonwood, box elder 
and elms,” and again, ‘the timber belt 
along the Nemaha River has widened from 
a hundred feet to half a mile and in some of 
the ‘draws’ it has run up from half a mile 
to a mile.”’ 
Another man speaks of a spot where 
“there is at present a fine lot of young 
timber of oak and hickory, where in 1876 
there was nothing but brush; it is fully one 
hundred yards further up the stream than 
it was in 1876.” He cites another case 
where the timber area has gone ‘nearly 
half a mile up the stream.’ He says that a 
fine grove of native timber through which 
I had passed a day or two before ‘‘ was a 
brush patch in 1874, very few of the trees 
then being large enough for fishing poles,”’ 
while now many of the trees are thirty or 
or more centimeters in diameter. 
Another observer records a grove consist- 
ing principally of oak trees from 15 to 30 
centimeters in diameter and 18 to 20 me- 
