166 BULLETIN OF WISCON'SIN NATURAL HISTORY SOCIETY. 
VOL. 2 NO. 3. 
Coming now to the tamarack belt, a brief study convinces one 
that this association is doomed to disappear, even without the in- 
terference of man. All its neighbors are making vigorous inroads 
upon its area. The shrubs from the salicetum are infringing on 
it, and have penetrated to its very heart. In some places, black 
ash, elm and other swamp-loving hardwood trees are encroaching. 
Even the sedges from the marsh are creeping in through every 
opening, especially along roads made through the swamp. On 
the other hand, reproduction of the tamarack is entirely wanting. 
There are no seedlings. The smallest trees are about three inches 
in diameter, and how old they may be can be guessed from the 
data given below. 
This tamarack swamp, like all I have ever seen in Southeastern 
Wisconsin, is very different from those in the Northern districts. 
Instead of having a peaty soil, and a floor composed of sphagnum, 
the ground flora is not very different from that of the ordinary 
black ash or willow swamp. Sphagnum mosses are not entirely 
absent, but comparatively unimportant and confined to the wettest 
portions. The numerous Ericaceae and allied types, so conspic- 
uous in the North, are absent. Only in the driest places, Pyrola 
rotimdifolia var. incarnata is found, often in the company of 
Majanthenmm hifoluim, Trientalis Americana, dind several mosses, 
especially of the genus Polytriclnim. 
During the past winter, some cutting had taken place in the 
swamp on the north side of the basin. The wood had been cut 
into billets and stacked, thus giving an opportunity to make some 
observations on the rate of growth of the tamarack. Twenty-one 
of the billets were measured and the annual rings counted with the 
following result : 
I. 
Diameter, 
6 
inches 
number 
of 
rings, 
37 
2. 
Diameter, 
6 
inches 
number 
of 
rings. 
43 
3- 
Diameter, 
5 
inches 
number 
of 
rings, 
43 
4- 
Diameter, 
6 
inches 
number 
of 
rings, 
44 
5- 
Diameter, 
5 
inches 
number 
of 
rings, 
50 
6. 
Diameter, 
7 
inches 
number 
of 
rings. 
71 
7- 
8. 
Diameter, 
7 
inches 
number 
of 
rings. 
73 
Diameter, 
5 
inches 
number 
of 
rings, 
39 
9- 
Diameter, 
4 
inches 
number of 
rings. 
36 
lO. 
Diameter, 
6 
inches 
number 
of 
rings. 
41 
II. 
Diameter, 
4 
inches 
number 
of 
rings. 
31 
12. 
Diameter, 
6 
inches 
number 
of 
rings. 
23 
13- 
Diameter, 
10 
inches 
number of 
rings, 
74 
14. 
Diameter, 
3 
inches 
number 
of 
rings, 
25 
15. 
Diameter, 
6 
inches 
number of 
rings, 
27 
16. 
Diameter, 
5 
inches 
number 
of 
rings, 
46 
