170 
FRANK C. GATES 
Reese's bog, the largest bog in the vicinity of the Biological Station, 
is a well-developed Thuja bog. Atmometer No. 34 was run near a 
Thuja seedling in the marginal foss at the foot of a hill, where the 
soil was ver}^ wet. Although exposed to the sun, the opportunity for 
free circulation was poor. Atmometer No. 35 was near a Thuja 
Fig. 8. View showing atmometer No. 21 near a pine seedling at the crest of a 
hill in an open aspen growth. The ground is carpeted with Gaultheria procumhens. 
August 9, 1915. 
.seedling in a dense thicket of 1 0-20-foot saplings in very wet soil — 
likewise hemmed in from the wind. Atmometers No. 32 and No. 33 
were in Thuja on slightly higher ground where the soil was dry at the 
surface and the circulation good — No. 32 in a slight opening in which 
a layered sprout was healthily growing and No. 33 in a very dense 
thicket of small trees under which was no green ground vegetation 
(Fig. 9). Ungerminated composite and Thuja seeds were found in the 
layer of dead Thuja leaves. Atmometer No. 31 was run by a Thuja 
seedling in a good-sized clearing where the seedlings were exposed to 
full sunlight. 
Atmometer No. 14 represents the evaporation conditions of the 
bare ground near the lake in the immediate vicinity of the laboratory, 
in 1915. 
In each experiment, unless otherwise noted, the atmometer was 
