SCIENTIFIC SURVEY OF TURNER’S LAKE 9 
Other combinations as given, except that the potassium in com- 
bination with organic matter will be correspondingly decreased. 
BARNARD S. BRonson.: 
At the south end of the lake flocks of herring gulls from outside - 
are, on summer days, ever cavorting in the soft waters, in their 
enjoyment of a fresh-water bath. It seems reasonable to suppose 
that some part of the potassium in the water may be due to their 
presence. Vien: 
THE BIOLOGY OF TURNER’S LAKE 
SHERMAN C. BisHop 
This narrow strip of water lies in a spoon of the island like an 
amber bar in a setting of green, gold and white. The cedars, maples 
and birches, banked steeply at the water’s edge, thinning somewhat, 
climb to the summit of the ridges that lie to the west and form 
the backbone of the island. Eastward a lower ridge follows the 
line of the lake and carries the road which traverses the woods 
at the north to Head Harbor at the southeast. At the south, the rocky 
barrier that pockets the slow waters beats back an encroaching alder 
swamp following the short outlet up from the sea; northward a gen- 
tle gravel slope, once cleared, brings to seed a crop of lusty weeds. 
Halfway down the west side, the rivulet Bull brook creeps in 
after a noisy journey over a rough bed, from its source in the 
sphagnum bogs on the axial ridge. The outlet leaves the southeast 
end in a tangle of undergrowth and stranded, rotting logs grown 
over with moss and ferns. 
The narrow trough filled by the lake seems to be a continuation 
of the swampy valley lying to the north which is held back at a higher 
line by the gravel slope which separates them. The lake itself has a 
length of only a little less than a mile and a quarter and an extreme 
width of about two hundred and twenty yards. At the north end 
where surface wash from the slope above has built up a sandy bottom, 
the water is shallow but south of this, in the mid-line of the lake, 
the depth regularly increases for five hundred yards to the maximum 
of fifty-six feet. South of this point for a thousand yards, the 
water gradually shallows marking a gentle rise of bottom leading 
to a rocky cross-ridge whose highest point is some twenty feet 
below the surface. The position of this drowned ridge is marked 
by a vertical white cedar log which rears a broken trunk a foot or 
two above the surface. The depth again increases to forty-eight feet 
midway between the tree and the boat landing at the south end of the 
