86 BIG SPRING PRAIRIE. 
surface covering of weeds and sedges swept over the 
greater portion of this thicket. In 1900, it was noted that 
less than half of the seedlings had succumbed to the 
flames. The remainder were still ina fair growing condi- 
tion, while on the bare spots many tree seedlings sprang 
up during this season. In 1901, this area was b:ought 
under cultivation, and thus ended any further observa- 
tions. The herbaceous vegetation in this thicket con- 
sisted chiefly of Urtica gracilis (Slender Nettle); Am- 
brosia trifida (Horse weed); Bidens (various species 
(Spanish needles); and Polygonum (various species) 
(Smartweeds); making a rank vegetation for the flames 
to act upon, and yet only a portion of the young trees 
were destroyed. 
On area B, of Map II, several trees from 8 to 12 in. 
in diameter were burned down in 1897, butin 1899 tree 
seedlings were already taking possession of portions of 
this area. In 1900, it was brought under cultivation, 
and no further stages could be noted. 
On Map I, other detatched areas of varying extent 
are indicated. Each case, upon examination, reveals 
the fact that destruction of sod is the potent factor in 
the introduction of weeds and tree seedlings upon Big 
Spring Prairie, and probably upon any of the eastern 
type of prairies. 
BURIED FORESTS. 
While some workmen were digging ditches on the 
H. B. Phelps Celery and Onion Farm just north of the 
woods showing settling of soil by the prominent roots, 
indicated on Map I, numerous trunks of trees were en- 
countered. The diameters of these trees vary from 6 
inches to about 3 feet. Near the Brown Ditch the tree 
remains occur near the surface, while further away 
the tree trunks were found at a depth of 2 to 4 feet. 
When this find occurred, the writer surmised that it 
might be a buried tamarack forest, but a microscopic 
